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Biomedical subjects

M R Ball

Publications and source records attributed to M R Ball.

54 records · Page 3Linked to original sources

Nitrogen sparing by carbohydrate in man: Intermittent or continuous enteral compared with continuous parenteral glucose.

To test whether oral carbohydrate would provide greater conservation of body protein than would intravenous carbohydrate, healthy normal human subjects were infused with high doses of glucose either continuously intravenously or by nasogastric tube in both continuous and intermittent regimes. Metabolic responses to high calorie, nitrogen-free infusions in normal man were documented in the blood hormone and substrate changes, and protein sparing was assessed by urinary nitrogen excretion. Continuous glucose produced a lower urinary "nitrogen floor" than did the intermittent regime, and intravenous glucose was more effective than was oral glucose. The insulin responses to continuous nasogastric and continuous intravenous glucose were similar, and nitrogen excretion did not differ between those two groups. The increased insulin levels seen with intermittent glucose were not accompanied by greater protein sparing.

Administration, Oral↗

Comparison of Doppler ultrasonography with arteriography of the carotid artery bifurcation.

Continuous-wave (CW) Doppler ultrasound imaging for prediction of arteriogrphic abnormality at the carotid bifurcation was carried out in 195 arteries of 105 patients. The Doppler method had no predictive value when compared to angiographic findings in arteries classified as 0-50% stenosis by Doppler. In 50-75% stenosis by arteriography Doppler accuracy was 52%. With stenosis of 76-99% Doppler imaging correlated with 71% reliability. When an arteriogram was compared with Doppler imaging the latter gave a "false negative" reading in 56% and "false positive" readings in 19%. We conclude that Doppler ultrasound evaluation provides important information regarding the state of the carotid bifurcation, which supplements the bedside evaluation, but it does not substitute for arteriography.

Adult↗

MRI of corpus callosal syndromes.

Six patients, 6 to 13 years old, with corpus callosal abnormalities diagnosed by electroencephalography or CT were studied with a 0.15 T MR imager to determine the effectiveness of MRI in evaluating midline anomalies. Spin-echo images in the coronal, axial, and sagittal planes were obtained in two patients with Aicardi's syndrome and partial agenesis of the corpus callosum, in one patient with Dandy-Walker syndrome, and in two patients with septooptic dysplasia. Inversion recovery and spin-echo images were obtained in one patient with lipoma of the corpus callosum. Partial agenesis of the corpus callosum was seen in septooptic dysplasia, an association that has not been reported previously in the radiologic literature. Direct sagittal and coronal MRI provided better anatomic visualization of the brain and ventricles than did reformatted CT. T1-weighted images are sufficient to diagnose and delineate the extent of midline cerebral abnormalities. The unique capability of direct sagittal imaging makes MRI the best procedure for evaluating corpus callosal and other midline abnormalities.

Abnormalities, Multiple↗

Chronic seizure disorders: contribution of MR imaging when CT is normal.

One hundred consecutive patients with complex partial seizures were studied by magnetic resonance (MR) imaging and computed tomography (CT). Thirty-four patients had seizures of more than 5 years' duration, yet neurologic examinations and previous pre- and postinfusion CT scans had been normal. MR imaging demonstrated surgical lesions of potentially therapeutic significance in four of these 34 patients. Two patients underwent surgery with removal of a thrombosed arteriovenous malformation and a glioma. Although CT has been found to detect structural abnormalities, its yield of therapeutically significant abnormalities has been low.

Adolescent↗

Neuroradiologic aspects of cerebral disseminated intravascular coagulation.

Six patients with neurovascular disseminated intravascular coagulation (DIC) illustrate the diversity of neuroradiologic changes in that condition. Emphasis is placed on the involvement of large cerebral vessels, especially as reflected by cerebral vein or sinus occlusions. The latter occurred in four of the six cases reported; deep or superficial veins, larger lobar draining veins such as the superficial middle cerebral vein, or large bore vessels such as the superior sagittal sinus or jugular bulb were involved. Radionuclide sinography or computed tomography (CT) was useful in revealing large vessel occlusions or their sequelae; in two cases CT showed focal hemorrhage in an unusual location. Although DIC has classically been envisioned as occurring within the arterial microcirculation, these cases attest to the occurrence of large vessel, especially venous, involvement in neurovascular DIC.

Adolescent↗