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Biomedical subjects

S N Chou

Publications and source records attributed to S N Chou.

At least 37 records · Page 2Linked to original sources
PubMed1980

Innervation of the external urethral and external anal sphincters in higher primates.

Stimulating electrodes were placed on the terminal branches of the pudendal nerve to the external urethral and external anal sphincters. The proximity of the electrodes to the sphincters assured organ specificity. Evoked responses produced by stimulation of these terminal nerve branches were recorded in the fascicles and rootlets of the lower thoracic, lumbar, and sacral nerve roots. By this method, the segmental spinal cord origin of the innervation of the external urethral and anal sphincters was determined for the Rhesus monkey and chimpanzee. The data indicated that the pudendal nerves to the urethral and anal sphincters in the Rhesus monkey arose from the sixth and seventh lumbar spinal segments and the first and second sacral spinal segments which are homologous to the S-1 and S-4 segments found to give innervation to these structures in the chimpanzee. The primate experiments thus indicate that the spinal origin of the pudendal nerve was more rostrally located by one segment or more than was the origin of the pelvic nerves to the urinary bladder.

Anal Canal↗
PubMed1980

Acupuncture.

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Acupuncture Therapy↗
PubMed1980

Combined embolization and operation in the treatment of cervical arteriovenous malformations.

The effectiveness of a combined approach of embolization and operation for cervical vascular malformations is stressed. Lesions that seem to be inoperable may have their blood flow sufficiently reduced by preoperative embolization to allow surgical extirpation. Polyvinyl alcohol foam is an ideal embolic agent; not only may it be used preoperatively, but its permanency allows it to be used for primary therapy.

Adolescent↗
PubMed1979

Superficial temporal to middle cerebral artery anastomosis. Clinical outcome in patients with ischemia of infarction in internal carotid artery distribution.

The clinical outcome of our first 40 patients (six with transient ischemic attacks, 22 with mild ischemic infarctions, and 12 with moderate ischemic infarctions) treated with a superficial temporal artery-middle cerebral artery anastomosis was analyzed. All cerebral ischemias or infarctions occurred in the internal carotid artery distribution. An independent neurologist observer recorded the patients preoperative and postoperative medical and neurological histories and objective neurological findings. There was no operative mortality. During the period of observation (up to 36 months), four patients died of probable myocardial infarction. No patient suffered from recurrent cerebral infarction. Three patients experienced a single ischemic event postoperatively. Neurological deficits were either unchanged (21 patients) or improved (19 patients). Postoperative angiograms showed patency in 97% of the anastomoses.

Adult↗
PubMed1979

Acute cerebral revascularization after regional cerebral ischemia in the dog. Part 2: Clinicopathological correlation.

The efficacy of cerebral revascularization by anastomosis of the superficial temporal artery (STA) to the middle cerebral artery (MCA), performed 4 and 24 hours after a regional MCA infarction had been produced by combined occlusion of the MCA and internal carotid artery, was tested in 12 dogs. To control possible intercurrent variables, seven other dogs remained untreated and five had a sham operation. Clinical and pathological changes were recorded and analyzed. An incidence of 85% infarction was obtained in the untreated control group. The severity of the clinical deficits and pathological changes for the anastomosed groups were greater than those seen in the untreated control group. The extent of the infarction was significantly greater (p less than 0.05) in the anastomosed groups than in the sham-operated and control groups. Hemorrhagic infarcts occurred in most of the dogs in the anastomosed groups, but were not present in either control group (p less than 0.05). Two dogs in the 4-hour and one in the 24-hour group improved more than any control dog, but the difference was not statistically significant (p greater than 0.05). In two dogs with occluded anastomosis the clinical deficits and the pathological changes were less than those seen in animals with patent anastomosis. The severity of the pathological and clinical changes correlated well with the reestablishment of flow in the MCA territory. It is proposed that cerebral revascularization at 4 and 24 hours following a regional MCA infarct in the dog is followed by an exacerbation of the microcirculatory obstruction, cerebral edema, and infarction. From improvement noted in three animals the authors suggest that under special conditions the revascularization could benefit some cases following acute cerebral infarction.

Animals↗
PubMed1979

Acute cerebral revascularization: part I. Cerebral ischemia experimental animal model.

Thirty-two mongrel dogs divided into two groups were subjected to a transorbital occlusion of the middle cerebral artery (MCA) or a combined transorbital MCA and cervical internal carotid artery (ICA) occlusion. Clinically apparent deficits were present in the MCA group in 18% of cases and in 73% of MCA/ICA cases. Pathologically, 55% of MCA cases and 73% of MCA/ICA cases had demonstrable areas of infarction. The incidence and severity of clinical deficits as well as the location and extent of pathological infarction were significantly greater (p less than 0.05) with the MCA/ICA group than in the MCA group. The mortality rate and frequency of pathologically apparent infarcts were not statistically different p greater than 0.05. No hemorrhagic infarctions were seen in any case.

Animals↗
PubMed1978

Hyperemia, CO2 responsiveness, and autoregulation in the white matter following experimental spinal cord injury.

The authors present the results of a controlled, randomized study of alterations in spinal cord blood flow, CO2 responsiveness, and autoregulation following experimental spinal cord injury in cats. Permanent paraplegia is shown to be associated with persistent hyperemia, loss of CO2 responsiveness, and impaired autoregulation in the white matter at the injury site. Probable mechanisms underlying these changes in spinal cord vasomotor control are discussed. Marked similarities between vascular responses of injured spinal cord and luxury perfusion of the brain are pointed out.

Animals↗
PubMed1978

Re-evaluation of differential sacral rhizotomy for neurological bladder disease.

The authors describe long-term follow-up results (4 to 6 years) in 13 patients who underwent differential sacral rhizotomy for urgency incontinence. Six patients were originally presented in a preliminary report in 1973. In the last seven patients, a highly selective rhizotomy of sacral fascicles innervating only the urinary bladder was performed. Results in the original six patients appear to be superior to those in patients who underwent a more refined rhizotomy. Possible explanations for this as well as alternative approaches to the treatment of urgency incontinence are briefly discussed.

Animals↗
PubMed1978

Surface topography of normal and neoplastic human anterior pituitary cells maintained in vitro.

Pituitary tissues were obtained from 25 patients who underwent surgery for excision of pituitary macroadenomas, selective excision of microadenomas, or removal of a normal gland for palliation of metastatic cancer. Cells thus obtained were maintained in vitro for varying intervals, fixed, and examined by light (phase contrast), microscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Previous SEM reports indicate that surface topography of in vitro neoplastic cells displays features that may correlate with neoplastic behavior. Cultured normal and pituitary tumor cells did not display these surface differences, with one exception, a prolactin-secreting microadenoma. Characteristic patterns for the cell populations were identified. Certain cell types appeared in all the cultures: 1) large and small granule-containing cells; 2) flat and irregular cells; 31 spindle-shaped cells; and 4) spherical, irregularly surfaced cells. In one case of an endocrine-inactive juvenile pituitary chromophobe adenoma, unique cells were observed. Surface topography did not appear to be of predictive value in determining the neoplastic character of pituitary tumors.

Adenoma, Basophil↗
PubMed1978

Lyle A. French.

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History, 20th Century↗
PubMed1978

Ipsilateral subclavian to external carotid and STA-MCA bypasses for retinal ischemia.

The surgical treatment of a patient with retinal ischemia in the left eye and occlusion of the left common and internal carotid and right internal carotid arteries is presented. After demonstration of filling of the left external carotid artery from vertebral collaterals, as saphenous vein graft from the left subclavian to the left external carotid artery was performed prior to a left superficial temporal artery to middle cerebral artery bypass. This case demonstrates the feasibility of revascularization in the presence of occlusion of the ipsilateral common and internal carotid arteries.

Blindness↗