Biomedical subjects
Publications and source records attributed to G Gardner.
Our experience in surgical treatment of 105 patients with cerebellopontine angle tumors is reported. Major emphasis is placed on a combined surgical approach and use of the CO2 laser. Our approach to diagnosis is also emphasized, as is the method we have used in compiling and collecting the data resulting from the study. Postoperative results and complications are reported and discussed.
Seventy patients suspected clinically of having an acoustic tumor were evaluated using the computed tomographic (CT) scan as the initial neuroradiological procedure, followed by CO2 contrast CT cisternography in cases where the intravenous contrast-enhanced scan did not reveal any lesion. Forty-eight gas CT cisternograms revealed 10 small acoustic tumors, 2 of which were totally intracanalicular. The authors present a review of the basic CT anatomy of the temporal bone as it relates to acoustic tumors. Based upon the ease of performance of the procedure, the low postexamination morbidity, and the excellent diagnostic results, CO2 CT cisternography is recommended as the procedure of choice in the diagnosis of small and intracanalicular acoustic tumors.
Total en bloc removal is the ideal surgical treatment for glomus jugulare tumours. Efforts to accomplish this have been made periodically since shortly after this tumour was first identified in the early 1940s. A method of removal using a combined approach through the neck and temporal bone is described here. This method is preceded by pre-operative irradiation therapy and on occasion by embolization. The early results obtained using this method in 19 patients are reported.
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2-Azido-4-ethylamino-6-isopropylamino-s-triazine (azido-atrazine) inhibits photosynthetic electron transport at a site identical to that affected by atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine). The latter is a well-characterized inhibitor of photosystem II reactions. Azido-atrazine was used as a photoaffinity label to identify the herbicide receptor protein; UV irradiation of chloroplast thylakoids in the presence of azido[(14)C]atrazine resulted in the covalent attachment of radioactive inhibitor to thylakoid membranes isolated from pea seedlings and from a triazine-susceptible biotype of the weed Amaranthus hybridus. No covalent binding of azido-atrazine was observed for thylakoid membranes isolated from a naturally occurring triazine-resistant biotype of A. hybridus. Analysis of thylakoid polypeptides from both the susceptible and resistant A. hybridus biotypes by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, followed by fluorography to locate (14)C label, demonstrated specific association of the azido[(14)C]atrazine with polypeptides of the 34- to 32-kilodalton size class in susceptible but not in resistant membranes.
Seven cases of jugulotympanic paragangliomas were studied with computed tomography (CT) and verified by angiography and surgery. All of five glomus jugulare tumors were detected and their extent accurately demonstrated by CT. Two small glomus tympanicum tumors were not convincingly demonstrated. Computed tomography is useful in investigating this neoplasm when it extends beyond the tympanic cavity or is associated with bone destruction.
A receptor protein for the auxin transport inhibitor, N-1-naphthylphthalamic acid (NPA), has been solubilized from corn coleoptile membranes using Triton X-100. [(3)H]NPA binding activity of the receptor was compared in soluble and membrane-bound states. Both activities are abolished by treatment with trypsin. Differences between the two are observed in pH optima and rates of heat inactivation.At pH 5, the membrane-bound and solubilized receptors have similar affinity for NPA (K(d) about 10(-7) molar). Solubilization results in a 10-fold increase in affinity for the low-affinity auxin analogs, alpha- and beta-naphthaleneacetic acid (K(d) about 10(-5) molar). There is no measurable competition by indoleacetic acid (K(d) > 10(-3) molar) for [(3)H]NPA binding to membranes, but there is competition with the solubilized receptor (K(d) for IAA about 10(-5) molar). There is no measurable competition with benzoic acid in either preparation. These observations of an affinity of auxin analogs for the solubilized NPA receptor raise the interesting possibility that the NPA binding site is one conformation of an auxin binding site involved in polar auxin transport.
Posterior fossa cisternography is a basic method for confirming the presence of acoustic and other tumors of the cerebellopontine angle. A modified outpatient procedure with use of new instrumentation is described here, and comparisons are made to the conventional hospital procedure. A series of patients selected for outpatient posterior fossa cisternography was studied using data processing techniques. Presenting symptoms and preliminary test results were compiled, and an impression established as to the likelihood of a tumor being present. Outpatient posterior fossa cisternography was performed, with examination under fluoroscopy in certain circumstances; surgery was performed in certain instances. The results of diagnostic procedures, surgical procedures, and follow-up studies were coded, analyzed by computer, and conclusions drawn.
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The ideal surgical treatment for glomus jugulare tumors is total removal. Efforts have been made periodically to accomplish this since shortly after this tumor was first identified in the early 1940's. This paper describes a method of removal using a combined approach through the neck and temporal bone, preceded by a course of preoperative irradiation therapy. The early results that have been obtained using this procedure in 10 patients are reported.
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This is a clinical study of the results of endolymphatic sac shunt surgery for Meniere's disease in 28 patients. Postoperative audiometric results and clinical evaluation of vertigo and tinnitus were analyzed to determine the effectiveness of this form of treatment. Although this is a small study and the time interval since operation is of only moderate duration (6 to 46 months), the results are encouraging: 79% of the patients showed improvement or stabilization of hearing as well as control of vertigo.
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