Publications

The San Francisco Bay Area Regional Poison Control Center studied 189 cases of toxic workplace exposure occurring over a six-month period in the belief that Regional Poison Control Center reporting could be a useful surveillance measure for occupational disease. Dermatitis was a relatively uncommon occurrence, but systemic complaints were frequent, a pattern differing from that seen in standard occupational surveillance programs. As compared to chemically caused illness detected through a statewide physician reporting program in California, increases in proportional frequencies of certain industrial chemical causes were observed. A matching strategy utilizing the physician reporting system identified only 15.9 per cent of poison control center cases that appear to have been otherwise detected through established surveillance. A nationwide system of Regional Poison Control Centers already exists with a computerized data base in place. This study indicates that these centers could be utilized as a supplementary system for acute occupational illness related to chemical exposures.

A procedure incorporating the salient features of ion-exchange column chromatography with ion-exchange h.p.l.c. is described for the fractionation and purification to homogeneity of several membrane-bound rat hepatic phenobarbital (PB)-inducible cytochrome P-450 isoenzymes, including the major PB-inducible species. The resolving power of this technique makes it a highly promising tool for the isolation and purification of closely related cytochrome P-450 isoenzymes. In addition, it may also be used for screening of individual isoenzymes either selectively induced or repressed by a variety of endobiotics or xenobiotics. Accordingly, we have exploited this particular feature to identify not only the PB-inducible cytochrome P-450 isoenzymes destroyed in vivo by allylisopropylacetamide, a suicide inactivator of cytochrome P-450, but also to distinguish those that are reparable by exogenous haemin from those that are irreparably damaged.

Dementia of the Alzheimer type (DAT) has proven to be difficult to diagnose using computerized X-ray tomography (CT). To improve the identification of DAT with CT, several different quantitative approaches have been tried. Brain parenchymal density measurements and a variety of linear indices of ventricular size have failed to reliably separate DAT patients from age matched controls. Measures of ventricular volume improve discrimination, but overlap with controls persists. The inadequacy of a single CT study to diagnose DAT is clearly related to the overlap of brain atrophy in DAT and healthy aging, a finding which has also been noted in post-mortem studies. Estimating the rate of ventricular enlargement from quantitative measurements of ventricular size on successive CT scans may allow the physician to take advantage of the progressive nature of DAT, improving separation of DAT patients from healthy controls.

Many techniques of rehabilitation require that the patient have intact cognition. This study determined the frequency of impaired cognition among the predominantly elderly patients on a community teaching hospital acute rehabilitation ward. The Cognitive Capacity Screening Examination (CCSE) was administered to 81 patients (ages 44 to 99, means 77, male:female 29:52). That 52 patients (64%) scored below 20 on the CCSE suggests significant cognitive impairment. The cognitively impaired patients were older than those with normal CCSE scores (p less than 0.05) and 19 patients had a prior history of chronic dementia. The physicians of 12 of the cognitively impaired patients (15% of all patients screened) were unaware of the impairment prior to their CCSE. Cognitively impaired patients scored similarly irrespective of a prior history of similar impairment (CCSE scores 10.2 +/- 1 for those without a prior history of dementia, 7.3 +/- 1.4 for those with prior dementia, p greater than 0.05). Physicians were more likely to be aware of a patient's current cognitive problems if the patient had a prior history of dementia (19/19 vs 21/33, p less than 0.01). The utility of employing a routinely administered CCSE to all patients accepted by a rehabilitation ward is emphasized. The time, cost, and effort of routinely performing such tests are negligible, and the potential benefits are considerable.