No abstract

A method is described for the estimation of microquantities of cyanide (or thiocyanate) ion. As little as 0.2 microgram of cyanide can be estimated with an accuracy of 99 * 4% standard deviation.Larger amounts of cyanide may be recovered with less deviation. ALTHOUGH many methods have been reported for the l microestimation of cyanides, few are both sensitive and reliable. The methods of estimation based upon the reaction of cyanides with picric acid (8) and the formation of Prussian blue (7) are comparatively insensitive. Good sensitivity has been acquired with the phenolphthalein %), o-cresolphthalein (8), and Aldridge (1) methods. The method described herein has the sensitivity of any of these, and in addition has the distinct advantage that it may be carried out in acid, neutral, or slightly alkaline media.Gehauf eí al. (£) used a pyridine-pyrazolone mixture for the detection of cyanogen halides. In this method, cyanogen chloride or bromide reacts with pyridine to form glutaconic aldehyde which forms a blue colored dye with 1 -phenyl,3-methyl, 5-pyrazolone.

An attempt has been made to identify and manage patients symptomatic from both cervical and lumbar spinal stenosis. The order of operative intervention was related to the degree of myelopathy and radiculopathy. Patients requiring cervical surgery first had absolute stenosis with a spinal canal equal to or less than 10 mm in anteroposterior diameter. Those requiring lumbar surgery first presented with stenosis and a canal between 11 and 13 mm in depth. In the latter group, patients presented with radiculopathy in their upper and lower extremities. A significant portion (50%) had intermittent neurogenic claudication (INC). Motor and sensory changes were severe in those with absolute as compared to relative stenosis. After cervical laminectomy, myelopathy improved or stabilized, and the subsequent lumbar decompression could be completed with less risk. Cervical cord decompression often resulted in improvement in lumbar symptoms with resolution of pain, spasticity, and sensory deficits of myelopathic origin. However, latent symptoms of INC caused by lumbar stenosis were not affected by cervial decompression and increased in severity. Electrodiagnostic studies were helpful in that somatosensory evoked potentials showed conduction delays in the cervical cord in patients with significant disease. The identification of motor neuron disease and peripheral neuropathies was essential. The surgical management included extensive, multiple level laminectomy, unroofing of the lateral recesses, and foraminotomy. Neurolysis and untethering of the spinal cord was essential. Significant improvement was shown by 90% of these patients.

No abstract