Biomedical subjects
Publications and source records attributed to F Epstein.
A 16-year-old boy was noted to have an apparent intradural sacral mass 6 weeks after the excision of a 4th ventricle ependymoma. Although spinal axis radiation was considered, it was decided to make a definitive tissue diagnosis. At sacral laminectomy, only segmental arachnoiditis was found. The implications of this finding are the subject of this case report.
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Explore the source record for details and available documents.
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Infants afflicted with meningomyelocele are paralyzed as a result of physiologic disconnection of the neural plate from the spinal cord. Intact neural elements within the placode often maintain segmental reflex innervation of paralyzed lower extremity muscles. It was hypothesized that bridging this central peripheral gap with viable intercostal nerves would restore limited voluntary movement to paralyzed muscles. The surgical technique and initial results are the subject of this report.
Zenker's solution is a tissue fixative containing mercuric chloride, potassium bichromate, sodium sulfate, and glacial acetic acid. In 1956, Anderson and Johnson reported its use in clinical neurosurgery. They applied the solution to the exposed dura after craniectomy. Delayed bone formation was thought to be due to the suppression of the osteoblastic activity of the outer layer of the dura. The fixative has since become a well-accepted adjuvant to the treatment of craniosynostosis. In 1972, Pawl and Sugar reported postoperative seizures in 6 of 34 patients treated with this solution. They assumed that the fixative penetrated the dura and irritated or damaged the cortex. To clarify the effect of Zenker's solution on the underlying brain, we performed bilateral parasagittal craniectomies in a group of kittens and adult cats. Zenker's solution was applied to one side and the other side served as a control. The animals were killed after periods varying from 24 hours to 2 months. We then examined the cortex under the craniectomies. There was immediate breakdown of the blood-brain barrier, as evidenced by the penetration of intravenous Evans blue. In the postoperative period investigated, an inflammatory response in the underlying brain with thickening of the arachnoid occurred. The results and implications of these experiments are presented. (Neurosurgery, 6: 45--48, 1980)
Infants afflicted with meningomyelocele are paralyzed as a result of the physiological disconnection of the neural plate from the spinal cord. Intact neural elements within the placode often maintain segmental reflex innervation of the paralyzed lower extremity muscles. It was hypothesized that bridging this central-peripheral gap with vaible intercostal nerves would restore limited voluntary movement to the paralyzed muscles. This procedure has been performed on four infants and seems promising.
The computed tomographic (CT) scan has replaced angiography in the preoperative neurodiagnostic evaluation of the common pediatric posterior fossa tumors. This case report illustrates that rarely an atypical vascular anomaly may masquerade as a neoplasm and angiography must not be dismissed if the CT scan is any way atypical of the suspected neoplasm.
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The typical CT appearance of intracranial arachnoid cysts may obviate additional neuroradiological procedures. Ventriculography using water-soluble contrast media may differentiate a suprasellar arachnoid cyst from a dilated third ventricle. Twelve cases are presented.
One-stage radical reconstructive surgery for the common craniofacial deformities has become standard procedure in a few medical centers. With increasing experience and expertise, young children and adolescents, as well as a few adults have been greatly benefited. It has long been recognized that both the cranial and facial deformities of Couzon's disease and Apert's syndrome are progressive, having their inception either before birth or in the neonatal period, and evolving to the full blown syndrome during the first years of life. The authors believe that the progressive nature of these anomalies is secondary to a combination of permaturely fused sutures of the calvarium and cranial base (coronal, sphenozygomatic, frontoethmoidal and frontosphenoidal). In an effort to arrest and correct both the cranial and facial deformities as well as obviate the need for future radical surgery the authors have treated several children with Crouzon's disease and Apert's syndrome with suture craniectomy along the base of the skull. Following this procedure, deformity has regressed and ultimate cosmetic improvement has been dramatic. It is unlikely that radical craniofacial surgery will be necessary in this group of patients at any future time. On the basis of this experience, it is believed that the pendulum is now swinging and that in the future, stripping of the appropriate sutures along the base of the skull will limit deformity and make additional surgery unnecessary.
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The cerebrospinal fluid (CSF) and serum of six patients with histologically verified intracranial germ-cell tumors were assayed serially for the presence of alphafetoprotein (AFP) and the beta subunit of human chorionic gonadotropin (HCG). Two patients had embryonal carcinomas, two had choriocarcinomas, and two had dysgerminomas. The marker profile for a given tumor in either CSF or serum correlated with the histological diagnosis; that is, embryonal carcinoma produced AFP and HCG, choriocarcinoma produced HCG, and dysgerminoma produced no markers. The marker levels in serum and CSF declined with therapy and rose usually prior to the development of overt clinical symptoms if the patient's tumor recurred. A CSF-to-serum gradient of the marker levels was present in three of four patients, and the serum levels were often normal when the CSF values were elevated. Ventricular marker levels were lower than the lumbar levels in two of two patients. The assay of these biological markers is a sensitive indicator of the success of therapy, and the presence of a CSF-to-serum gradient suggests that the major portion of the neoplasm rests within the central nervous system. A histological diagnosis can be inferred without the necessity of surgery in appropriate clinical contexts.
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22 cases of pediatric posterior fossa tumors that underwent preoperative evaluation by computerized tomography are presented. 8 of the cases, in the latter part of the series, were successfully operated upon on the basis of computerized tomography alone. In 14 other cases, additional angiographic investigation was carried out. In only 1 case of multiple hemangioblastoma did angiography provide further significant information. On the basis of this experience, it is suggested that computerized tomography is usually sufficient and further contrast studies are unnecessary in the preoperative evaluation of pediatric posterior fossa tumors.
Ouabain circulating in blood inhibits Na-K-ATPase in the gills of seawater eels at a concentration similar to that necessary for inhibition in vitro. By contrast, a much higher concentration is required when ouabain is applied to the exterior of the gill. Inhibition by external ouabain occurs only when the drug gains access to the circulation of the fish, as evidenced by simultaneous inhibition of Na-K-ATPase in the kidney. These results suggest that the Na-K-ATPase of gill chloride cells faces inward, lining intracytoplasmic tubular channels continuous with the extracellular fluid. Inhibition of gill Na-K-ATPase by ouabain in intact salt water eels results in almost complete inhibition of the efflux of both Na+ and Cl-. The efflux is tritiated water was much less reduced, to 60% of normal. Since chloride is actively transported outward across the gill of seawater teleosts, it is suggested that active chloride transport is coupled to Na-K-ATPase. A neutral sodium chloride carrier is postulated that is energized by the movement of sodium from extracellular fluid down its electrochemical gradient into the chloride cell.