Root avulsion in brachial plexus injury: a case report.

Root avulsions in brachial plexus injuries are classified as pre- or infraganglionic or post- or supraganglionic. Motor and sensory function is lost in both lesions, but the dorsal root ganglion is intact in preganglionic injuries and, therefore, sensory nerve conduction is spared. Although classified as root avulsion lesions, they are not only anatomically but physiologically and in being amenable to surgical treatment, quite different. We describe a patient with preganglionic injury who had a normal sensory nerve conduction. Surgical option was not available to this patient because of the proximity of the avulsed roots to the spinal cord.

A cerebrospinal fluid glucose biosensor for diabetes mellitus.

A cerebrospinal fluid (CSF) glucose biosensor is introduced. The biosensor is a polarimeter that measures the rotation of plane polarized light proportional to glucose concentration. Preliminary in vitro studies revealed a linear response with good sensitivity over a range of glucose solutions (0-400 mg/dl). Anesthetized, adult dogs underwent intravenous glucose loading, and these preliminary in vivo studies resulted in good correlation (r = 0.98) between CSF polarimeter readings and CSF glucose by laboratory assay. This in vivo correlation suggests that both mutarotation of glucose anomer and changes from other optically active substances present in CSF are either negligible or constant over the range of glucose concentrations studied. The CSF polarimeter showed a significant rise soon after the intravenous loading of glucose (1-30 min) but a longer lag time (45-60 min) between the peak blood glucose and peak CSF polarimeter reading. This preliminary work extends, to the CSF, the concept of measuring optical rotation.

Hematocrit monitor.

The purpose of this study is to determine experimentally the optimal incident visible wavelength and light detector angle that yields the maximal change in optical density between an arterial or venous Hct of 20% and 40%. A universal monochromator allows incident wave-lengths in 8-nm increments over the visible range to be selected for the incident beam and a motorized shuttle allows the two samples (Hct 20% and 40%) to be placed reproducibly between the incident beam and photodiode detector. Runs performed with the light detector at a 30 degree, 90 degree, and 180 degree angle from the incident light beam revealed the greatest change in optical density between an Hct of 20% and 40% to occur at 624 nm and 90 degrees independent of sample cell configuration, light source profile, or light detector profile. This experimentally determined optimal wavelength and angle are utilized in a fiberoptic biosensor to monitor Hct successfully in dogs undergoing surgical procedures.

Use of the Amplatz heparin-coated wire guide to facilitate placement of the Hickman catheter.

We describe herein a technique in which a special type of j wire guide and fluoroscopy are used to facilitate the placement of Hickman catheters in patients in whom this is technically difficult. This method is quick and safe and allows for direct visualization in the placement of the catheter.

Asymptomatic carotid arterial disease in patients presenting with angiographically proven coronary artery disease.

Atherosclerosis is a systemic and progressive disease process. However, the patterns of disease and the sequence of arterial involvement need further definition. A select group of patients initially presenting with coronary arterial disease was evaluated for evidence of hemodynamically significant carotid arterial disease. Eight per cent of patients were found to have hemodynamically significant carotid arterial disease by the oculopneumoplethysmography (Gee OPG). This low incidence of carotid arterial disease is in contrast to patients who present with carotid arterial disease who are found to have a high incidence of coronary artery disease. This would suggest that either the coronary artery disease develops first or that there is a specific pattern of atherosclerotic vascular disease where patients have coronary artery disease without hemodynamically significant carotid disease. Long-term follow-up on patients initially presenting with coronary arterial disease will help further define this question.