The effects of Alzheimer disease on driving-related abilities

Ten Alzheimer disease (AD) patients and 12 healthy elderly controls were evaluated on two tests of driving-related abilities: the Driver Performance Test (DPT) and the Driving Advisement System (DAS). Subjects were administered a battery of neuropsychological tests to determine if severity of dementia in AD correlates with driving performance. On the DPT, the AD patients scored in the average range in two of five skill areas (predicting the effects of a hazard, deciding how to avoid it); below average in two areas (searching for a hazard, executing evasive actions); and poorly in one area (identifying hazards). The elderly controls scored at an average level in all five skill areas. On the DAS, AD patients were significantly slower than the elderly controls on simple, two-choice, and conditional reaction time tests and were much slower than drivers in general. The AD patients' performances on two cognitive tests, the Mini-Mental State Examination (MMSE) and the Category Fluency Test, correlated significantly with aspects of performance on the DPT and the DAS. Although these are preliminary results from a pilot investigation, they suggest that AD patients' driving-related abilities are adversely affected by the disease and that driving-related performance tests and neuropsychological tests may be useful in assessing the impact of AD on driving.     

Greater contractility of internal mammary artery bifurcation: possible cause of low patency rates

Coronary artery bypass grafting using bifurcation of the internal mammary artery (IMA) has been reported to have a poor patency rate. To test the hypothesis that the contractility (tendency for spasm) is greater at the bifurcation than at the main IMA, segments of the bifurcation and the distal section of IMA taken from patients with coronary artery bypass grafts were studied in organ baths. The IMA rings were set up at a physiologic pressure. Concentration-response curves were established for norepinephrine, endothelin-1, U46619, potassium, and glyceryl trinitrate (precontracted with 10 nmol/L U46619). Contraction forces were standardized (gram per mm circumference) at a pressure of 100 mm Hg. The diameter was 1.50 +/- 0.08 mm (n = 38) for the bifurcation and 2.03 +/- 0.07 (n = 42) for the main IMA (p < 0.0001). The standardized contraction force was greater in the bifurcation than in the main IMA for norepinephrine (0.82 +/- 0.06 versus 0.54 +/- 0.1; p = 0.02) and endothelin-1 (1.07 +/- 0.11 versus 0.69 +/- 0.07; p = 0.02). No differences were seen for potassium, U46619, or glyceryl trinitrate, whereas the effective concentration that induced 50% of maximal effect for U46619 was 6.17-fold lower in the bifurcation than in the main IMA (9.14 +/- 0.28 versus 8.35 +/- 0.09 -log M; p = 0.003), indicating higher sensitivity in the bifurcation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of a heroin esterase in Rhodococcus sp. strain H1

A strain of a Rhodococcus sp. (termed H1) capable of utilizing heroin as its sole carbon and energy source was isolated by selective enrichment. An inducible heroin esterase was partially purified and shown to catalyze the hydrolysis of both of the acetylester groups of heroin. The enzyme displays optimum activity at pH 8.5 and appears to be a trimer of identical subunits with an M(r) or 39,000 and a native M(r) of 120,000.     

Giant recurrent desmoid tumor: a case report

A case of giant recurrent intra-abdominal desmoid tumor is presented. A history of childbirth, antecedent surgery, multiple episodes of recurrence, resistance to excisional and radiation therapy, represent common features of desmoid tumors. The size of the recurrence (15.4 kg), the intra-abdominal presentation of the tumor, involvement of the chest wall and focal infiltration of the small bowel are unusual features of this case.     

Rapid thin layer chromatographic method for the detection of histamine in fish products

A rapid, convenient thin layer chromatographic (TLC) method for detecting histamine in fish samples is described. Samples of press juice or fish flesh are applied directly to TLC plates. The plates are developed with acetoneammonium hydroxide (95+5) and the spots are visualized with ninhydrin or Pauly's reagent. Chromatographic separation of histamine from other fish components is readily achieved by this method.     

Metabolism of catechol estrogen by human erythrocytes

In a study designed to evaluate the kinetics of catechol estrogen formation from plasma estrone in vivo, we obtained evidence that the red blood cell (RBC) enzyme, catechol-O-methyl transferase, catalyzes the transformation of 2-hydroxyestrone to 2-methoxyestrone. Under in vitro conditions, the rate of conversion of 2-hydroxyestrone to 2-methoxyestrone by human RBC's was such that 7 nmol of 2-methoxyestrone were formed per h per ml of RBC.     

Abnormal aminopyrine metabolism in patients with hepatic neoplasm. Detection by breath test

Aminopyrine metabolism was assessed by the aminopyrine breath test (ABT) in 153 patients with malignant disease, of whom 75 had hepatic neoplasm and 78 had none. Radioactive carbon dioxide (14CO2) exhalation was measured two hours after oral administration of a trace dose of carbon-14 labeled aminopyrine. The ABT was correct in 62 of 75 (83%) patients with hepatic neoplasm and in 73 of 78 (94%) patients without. It was correct in 16 of 22 (73%) patients who had hepatic neoplasm without abnormal serum biochemistry. Aminopyrine metabolic clearance rate (AMCR) was 32.4 ml/min in patients with hepatic neoplasm and 103.4 +/- 18.8 ml/min in the patients without. There was a highly significant correlation between ABT and AMCR (r =.76, P less than .01). We conclude that aminopyrine metabolism is depressed in most patients with hepatic neoplasm and that the ABT affords a useful method for detecting malignant tumors of the liver.