Search

Computed tomography demonstrated contrast-enhancing lesions in the periventricular frontal regions, caudate nuclei, and thalami in an infant with Alexander's disease. The distribution of the enhancing lesions corresponded to the areas in which Rosenthal fibers were most prominent. These radiological findings have not been described in other white matter diseases; thus, they may help to distinguish Alexander's disease from Canavan's disease and decrease the necessity for diagnostic brain biopsy.

In a review of all children with brain neoplasms evaluated at a large pediatric center during a three-year period following the introduction of computed tomography (CT), a change was observed in the age distribution at the time of clinical presentation as compared with a previous series evaluated prior to the introduction of CT. In children under six years of age, there was a highly significant trend for earlier diagnosis; within this age group, relatively more children were diagnosed in the first two years of life. Between six and twelve years of age, there was no change in frequency of brain tumor diagnosis between the two series. Above age twelve, there was again noted a highly significant increase in detection of brain tumors in the more recent series. These differences between the two series may be attributed, at least in part, to earlier referral and diagnosis since the advent of CT, although other factors cannot be excluded as possible causes of the differences.

Expiratory collapse of the trachea was demonstrated radiographically in three infants with esophageal atresia who developed episodes of severe upper respiratory obstruction in the first few weeks of life. The abnormality is most readily seen fluoroscopically in such patients, though tracheal narrowing may be visible on an expiratory lateral chest radiography. An unusually long tracheostomy tube may be required to bypass the site of obstruction.

Computed tomographic metrizamide myelography (CTMM) is an accurate and satisfactory method for examining the spinal cord in infants and children. Twenty-three patients with spinal dysraphism have been studied by CTMM. This method has proven more informative than conventional myelography in the evaluation of the dysraphic state.

This paper presents a theoretic study of pharmacokinetic and cell kinetic models for cancer chemotherapeutic systems. The mathematic analysis is based on a modified procedure deduced from DeVita's scheme of the relationship between the cellular kinetics of normal and tumor tissues and the pharmacokinetics of antitumor agents for designing an optimal dose and schedule for cancer treatment. In this scheme pharmacokinetic models and cell-drug interactions at the tumor site are incorporated into the cell cycle kinetic models to form the cancer chemotherapeutic model systems. Three cell cycle kinetic models are presented under alternative hypotheses concerning the mechanism of the resting cells, while each tumor mass is comprised of cells in proliferating (consisting of the four cycle phases G1, S, G2, and M), resting (Go), and non dividing (D, dead) states. An algorithm and a computer program for simulating the tumor populations during scheduled treatments have been prepared. By a suitable selection of expressions for cell-drug interactions, the program is able to simulate tumor behavior during scheduled treatments with different classes of anticancer agent such as cell cycle phase-specific, cell cycle-specific, or cell cycle-specific, or cell cycle-nonspecific drugs. A preliminary study of the L1210-ara-C therapeutic system is included to demonstrate the computer simulation procedures.

Moyamoya disease is a progressive disorder, predominantly seen in childhood, that can cause severe permanent disability. The search for effective treatment has largely been unsuccessful in the past, but recent efforts at surgical intervention have shown promising results. The natural history of moyamoya disease, the options for treatment, and a series of patients from the Hospital for Sick Children in Toronto are reviewed. The results of surgical treatment are encouraging and the authors believe that it should be offered to all pediatric patients in the progressive stage of the disease.