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Biomedical subjects

S N Chou

Publications and source records attributed to S N Chou.

At least 55 records · Page 3Linked to original sources
PubMed1977

Radionuclide bolus angiography: a technique for verification of brain death in infants and children.

Fifteen infants and children, 11 of whom had clinical brain death and four of whom were comatose, were evaluated with the radionuclide bolus study and electroencephalography. Clinical criteria for brain death included: (1) absence of spontaneous respirations, (2) absence of cephalic reflexes, and (3) unresponsiveness. Results demonstrated complete correlation among clinical examination, EEG, and radionuclide study in 79% of cases. An approach to the evaluation of the infant or child with possible brain death is outlined utilizing serial examinations, radionuclide bolus study, and electroencephalography. The radionuclide bolus study appears to be a safe, rapid, portable technique which can be used for this purpose in infants and children.

Angiography↗
PubMed1977

Immunoproteins in human brain tumor cyst fluids.

Quantitation of the concentration of immunoproteins in serum, and cystic fluids from six patients (three with cerebral astrocytoma and three with cerebellar hemangioblastoma) has been determined. The values for total protein, albumin, immunoproteins IgG, IgA, and IgM, and C3C (complement) in cyst fluid more closely correspond to serum than to cerebrospinal fluid values. Values for cyst fluid, cerebrospinal fluid, and serum were determined using albumin ratios in order to compare relative differences between fluids from these three compartments. Our data suggests that: 1) the major protein content of brain tumor cyst fluid is consequential to a transudative process from serum, and 2) that immunoglobulins IgG and IgA are present in higher concentrations in human brain tumor cyst fluids in comparison to IgM concentrations. These studies further question the concept of the brain as an "immunological privileged site", and may be of direct relevance to the investigation of the use of immunotherapeutic modalities as an adjunct after surgical tumor removal.

Adolescent↗
PubMed1977

Aneurysmal tumors of the basifrontal region.

The authors report the cases of three men who presented for evaluation of a rapidly progressing dementia. All were found to have a giant aneurysmal mass in the basifrontal region, and all were successfully treated by surgical excision of the mass. The presenting syndrome included rapidly progressive and severe loss of recent memory associated with confusion, chronic headache, wide-based staggering gait disturbance, urinary urgency, frequency, and incontinence, and a fine tremor of the hands exacerbated by purposeful movements. The clinical presentation, radiological assessment, and surgical treatment are discussed.

Dementia↗
PubMed1977

Prognosis of seventh nerve palsy following removal of a large acoustic tumors.

Before the advent of microsurgery for acoustic tumors, it was accepted that the majority of seventh nerves would be lost during the removal of large tumors. It is now possible to preserve these attenuated seventh nerves, even with very large tumors. Postoperative facial palsy may be present even with an anatomically intact seventh nerve, but our experience has demonstrated that recovery will ultimately occur. Eight of our nin patients with this situation have regained facial function, although in some the first clinical evidence of recovery did not occur for 1 year.

Facial Nerve↗
PubMed1977

The treatment of paralysis associated with kyphosis: role of anterior decompression.

A multi-disciplinary team approach is essential to achieve good results and to reduce morbidity and mortality from anterior spinal cord compression due to kyphosis. There are several procedures for the individual patient management. The absolute indication is progressive neurological deficit. Preoperative investigations should include detailed neurological, neuro-urological, roentgenological and myelographic and pulmonary function measurements. Intraoperative management of patient positioning, exposure, ostectomy, hemostasis and replacement of blood loss require special attention. Postoperative and long term follow-up observations are necessary for good patient care.

Follow-Up Studies↗
PubMed1977

Harrington instrumentation and spine fusion for unstable fractures and fracture-dislocations of the thoracic and lumbar spine.

Of forty patients with unstable fractures and fracture-dislocations of the thoracic or lumbar spine treated with Harrington instrumentation and spine fusion, thirty-five had a neural deficit (twenty-three with incomplete or cauda equina lesions and twelve with complete lesions). Laminectomy or posterolateral decompression was performed prior to instrumentation and fusion in twenty-three patients and at the time of stabilization, in thirteen. Solid fusion was obtained in all but one patient. Back pain persisted in four. No patient had residual spinal deformity. Twenty-one patients with incomplete or cauda equina lesions regained some neural function, while all twelve with complete lesions remained unchanged. The advantages of this technique include effective stabilization of the spine, early mobilization and rehabilitation, and prevention of late deformity.

Adolescent↗
PubMed1976

Cerebral arterial spasm. Part 4: in vitro effects of temperature, serotonin analogues, large nonphysiological concentrations of serotonin, and extracellular calcium and magnesium on serotonin-induced contractions of the canine basilar artery.

In vitro experiments were performed using a small volume chamber to study serotonin-induced contractions of the canine basilar artery. Temperature was found to have a profound effect on the artery's response to serotonin. Raising the temperature to 40 degrees C (104 degrees F) increased the maximum response by 20% and lowering the temperature by 10 degrees C caused a 40% reduction in the maximum contraction. Cumulative log-dose response curves for analogues of serotonin demonstrated a high degree of specificity for the serotonin receptor and large nonphysiological concentrations of serotonin caused relaxation of the contracted artery. Extracellular calcium was shown to be an absolute requirement for serotonin-induced contractions. Extracellular magnesium, in contrast, was shown to inhibit serotonin-induced contractions.

Animals↗
PubMed1976

Cerebral arterial spasm. Part 5: in vitro contractile activity of vasoactive agents including human CSF on human basilar and anterior cerebral arteries.

In vitro experiments were performed with a small volume chamber to determine the contractile activity of various vasoactive agents on human basilar and anterior cerebral arteries. Cumulative log-dose response curves were obtained for most of the agents tested including serotonin and three different prostaglandins; many of these curves were found to be similar to curves previously obtained with canine cerebral arteries. It was concluded from these similarities that canine cerebral arteries are a good in vitro model for studying human cerebral arterial spasm. It was also demonstrated that human cerebrospinal fluid, collected up to 17 days after a subarachnoid hemorrhage from patients with clinical and angiographic evidence of cerebral arterial spasm, would cause large, dose-dependent contractions in human anterior cerebral arteries.

Adolescent↗
PubMed1976

Spectrum of the hangman's fracture.

The authors review their experience in managing 26 cases of "hangman's fracture." The basic mechanism of injury was hyperextension of the upper cervical spine. Radiographic studies revealed a spectrum of injury beginning with the classical hangman's fracture and progressing to the simple C-2 laminar-pedicle fracture. Appreciation of the fracture instability will dictate the method and duration of fracture treatment. Management by a closed, nonoperative means resulted in solid union of the bone in all fully treated cases, with a minimum of morbidity.

Accidents, Traffic↗
PubMed1976

Electrophysiological technique for evaluating lesions of the conus medullaris and cauda equina.

The authors describe the use of evoked electromyographic responses recorded in the anal sphincter induced by stimulation of the bladder wall and urethra in evaluating lesions of the conus medullaris and cauda equina in 110 patients. This reflex response took effect by way of the pelvic nerves and cauda equina to the sacral cord where the pudendal nerve nucleus was activated, resulting in a contraction of the external anal sphincter. Various lesions along this pathway have been shown to produce either increased latencies and depressed responses or complete loss of response depending on the extent of the lesion. The correlation of results of this technique with clinical, myelographic, and operative findings indicate it to be a useful clinical tool.

Anal Canal↗
PubMed1976

Topographical anatomy of human cerebral and cerebellar astrocytomas in vitro.

This study further characterizes the morphological and in vitro properties of human neoplastic cells derived from one Grade IV cerebral astrocytoma and one Grade III cerebellar astrocytoma. Light microscopic observations performed weekly over a four month period revealed two morphologically indistinguishable cell populations in each of the tumor cultures. Scanning electron microscopy demonstrated the presence of microvilli, blegs, and ruffles on the cell surfaces of both tumors; however, these topographical features were more prominent in the cultures derived from the Grade III cerebellar astrocytoma. Scanning electron microscopy may provide a useful tool for the further morphologic classification of human astrocytomas.

Adult↗