Search Results

You are looking at 1 - 10 of 20 items for

  • Author or Editor: John Mealey Jr x
Clear All Modify Search
Restricted access

Radioisotopic Localization in Subdural Hematomas

An Experimental Study with Arsenic-74 and Radioiodinated Human Serum Albumin in Dogs

John Mealey Jr.

Restricted access

Gamma-Ray Image of Subdural Effusions

Scanning after Injection of Radio-Iodinated Serum Albumin into Subdural Space and Its Clinical Application

John Mealey Jr.

Restricted access

Julius M. Goodman and John Mealey Jr.

Restricted access

Richard L. Gilmor and John Mealey Jr.

✓ A case of the cranial form of a melanotic neuroectodermal tumor is reported in an infant, and similar cases reviewed in seven other patients. The predilection of this tumor for the anterior fontanel region, its rapid invasion of adjacent bone, and its predominance to date in Negro males are documented. The prognosis appears to be excellent after simple excision and electrocautery of the dural extension. The probable origin and pathological features are discussed.

Restricted access

Jans Muller and John Mealey Jr.

✓ A solid, extrinsic hemangiopericytoma of the cerebellopontine angle was studied histologically and by means of tissue culture. The explanted tumor cells formed classic meningiomatous whorls indicative of the meningeal derivation of this neoplasm. Whorls were entirely absent in the histological preparations, however. The cases reported under the diagnosis of intracranial hemangiopericytoma and angioblastic meningioma have been reviewed; no valid histological distinction between these two types could be made.

Restricted access

Thomas R. Keucher and John Mealey Jr.

✓ This series of 228 patients with infantile non-neoplastic hydrocephalus who received either a ventriculoatrial (VA) or a ventriculoperitoneal (VP) shunt before 2 years of age was followed for an average of 7 years, and the results with the two types of shunt were compared. Mortality and infection rates were similar for both groups of patients, but children with VP shunts required significantly fewer revisions and had a much greater likelihood of not having any revisions during the follow-up period. Late complications occurred more frequently with VA shunts and were more serious. It is concluded that VP shunts offer significant advantages over VA systems in this population.

Restricted access

John Mealey Jr., Andrievs J. Dzenitis and Arthur A. Hockey

Restricted access

John Mealey Jr., Tsu T. Chen and George P. Schanz

✓ Eight biopsied glioblastomas were propagated in vitro through multiple, serial cell cultures which were exposed to dexamethasone and methylprednisolone in concentrations ranging from 0.25 to 400 µg/ml. The higher concentrations of both steroids produced inhibition of culture growth and cytotoxic damage which appeared relatively nonspecific. Although the responses observed were dose-dependent, the sensitivity among glioma cultures of different origins varied. Of the two steroids, Methylprednisolone was more injurious to glioma cells in vitro and was cytolytic in doses of 400 µg/ml. Growth inhibition was demonstrated after a 1-day exposure to this corticoid, but this effect was usually transient at lower doses. Thereafter, surviving resistant cells resumed their natural rate of growth in the continued presence of the steroid as well as under standard conditions of culture. Potential clinical applications of the antineoplastic properties of corticosteroids against the gliomas are discussed, emphasizing the need to investigate additional, possibly more efficacious compounds.

Restricted access

John Mealey Jr., Tsu T. Chen and Robert Shupe

✓Individual and combined effects of ionizing radiation and chemotherapy with 1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU) on glial tumor cells were assessed in cultures derived from human glioblastomas. Drug and radiation exposures were performed on cell monolayers in 0.02 ml wells of microtest plates. Response to treatment was determined from serial observations on surviving populations in the original wells and comparisons with matched control cultures. Chemosensitivity was more variable than radiosensitivity in cell lines derived from five different glioblastomas: BCNU caused growth inhibition of 4% to 85% in doses of 8 µg/ml for 3 days compared to a 40% to 73% reduction after 400 rads of radiation. These findings were all significant statistically. Single doses above 600 to 800 rads appeared lethal, causing widespread loss of cells or transformation into giant forms that did not multiply. The doseresponse curves after BCNU and radiation treatment of cultured glial tumor cells were exponential, demonstrating that both modalities affected a constant fraction of the exposed cell populations according to dose. The observations on radiosensitivity of human glial tumor cells conformed to the generally known responses of cultured normal and neoplastic mammalian cells to ionizing radiation. BCNU in the higher doses tested acted as a possible radiosensitizing agent to potentiate the lethal effects of radiation since an increased rate of cell loss was demonstrated in glioma cultures exposed to this drug and radiation compared to those treated only by irradiation. These results in a controlled experimental environment support the concept that a combination of BCNU and radiation therapy should increase the time of survival of patients with malignant gliomas.