Biomedical subjects
Publications and source records attributed to H R Townsend.
A 16-year-old woman deliberately took a large, toxic overdose of carbamazepine and recovered despite a high plasma level. During the acute phase the EEG was dominated by occipital delta activity suggestive of a brainstem disorder. Following 24-h treatment with activated charcoal the plasma carbamazepine was cleared and the EEG returned to normal.
The paper describes a Basic Operating and Scheduling System (BOSS) designed for a small computer. User programs are organised as self-contained modular 'processes' and the way in which the scheduler divides the time of the computer equally between them, while arranging for any process which has to respond to an interrupt from a peripheral device to be given the necessary priority, is described in detail. Next the procedures provided by the operating system to organise communication between processes are described, and how they are used to construct dynamically self-modifying real-time systems. Finally, the general philosophy of BOSS and applications to a multi-processor assembly are discussed.
A man of 51 years presented with sudden onset of a confusional state and marked visual deterioration. The computerised transaxial tomogram showed a mass in the corpus callosum which had spread to involve both cerebral hemispheres. The visual evoked potential to pattern stimulus was delayed by about 20 ms. Necropsy confirmed the presence of an astrocytoma of the corpus callosum involving the optic radiation and occipital cortex on both sides. The anterior visual pathway was normal.
During the investigation of a familial neurological disease of cattle with some similarities to human epilepsy serial sampling of lateral ventricular and cisternal cerebrospinal fluid and of electrocortical activity was undertaken. In this paper the surgical approach, the technical problems encountered and some solutions are discussed. Further possibilities for the development and application of the technique are indicated.
A homogeneous sample of 14 patients with advanced chronic bronchitis and emphysema complicated by secondary polycythaemia and pulmonary hypertension was examined. Eight patients who were receiving long-term oxygen therapy (LTO2) for 15-20 h in the 24 h day showed a significantly faster, that is more normal, frequency of the dominant EEG activity and a higher level of arterial oxygenation when breathing air than six similar patients not receiving LTO2. Acute administration of oxygen (2 1/min) for 15 min did not change the EEG pattern in either group of patients. The frequency of the dominant EEG activity in all 14 patients showed a significant positive correlation with the arterial oxygen saturation and negative correlation with the level of polycythaemia. Occurrence of intermixed EEG show activity theta and delta was positively correlated both with hypoxaemia and hypercapnia. The results suggest that the LTO2 in patients with chronic ventilatory failure has a beneficial effect on cerebral function as measured by EEG.