Motor vehicle accidents in Parkinson's disease: A questionnaire study

OBJECTIVES

Few studies have investigated the risk factors for motor vehicle accidents (MVA) in individuals with Parkinson's disease (PD) in Japan.

MATERIALS AND METHODS

We sent an anonymous questionnaire to 1417 patients with PD who had received medical care certificates for Intractable Diseases during the 2014 fiscal year from the Aomori Prefectural Government in Japan. Data from patients with PD who previously or currently held a driving license at the time of the survey were analyzed.

RESULTS

Complete datasets were obtained from 384 patients with PD who were either past or present driving license holders. Fifty-seven patients had caused at least one MVA in the last 5 years before the survey. Logistic regression analyses revealed that ergot-dopamine agonist (DA) use and excessive daytime sleepiness (Epworth Sleepiness Scale score ≥ 10) were the best predictors of MVAs. Patients having caused non-sleep-related MVAs had significantly longer disease durations, more frequent ergot-DA use, and higher cognition and communication subscores on the Parkinson's Disease Questionnaire-39 than those without non-sleep-related MVAs (P < .05). The Epworth Sleepiness Scale scores of PD patients with sleep-related MVAs were significantly higher than those of patients without sleep-related MVAs (P < .01).

CONCLUSIONS

Excessive daytime sleepiness and ergot-DA use may be important predictive risk factors for MVAs in PD. Daytime sleepiness appears to be related to sleep-related MVAs in PD, whereas disease progression and ergot-DA use may contribute to non-sleep-related MVAs.

High cell density suspension culture of mammalian anchorage independent cells: Oxygen transfer by gas sparging and defoaming with a hydrophobic net

Gas sparging directly into the culture-broth is not done in cell culture, except when the gas flow rate is very small, because much foaming occurs. During screening of defoaming methods, foam was observed to be broken up effectively when it made contact with a net fabricated from hydrophobic materials. Providing a highly efficient oxygen supply to suspension culture was tried using the new defoaming method. In a 5 l reactor equipped with the foam-eliminating net fabricated with polysiloxane, oxygen was transferred at 21 mmole/l.h equivalent to a consumption rate of 1 X 10(8) cells/ml, even at a low oxygen gas flow rate of 0.1 cm/s corresponding to a fourth of the gas flow rate when foam leaked through the net. Perfusion culture of rat ascites hepatoma cell JTC-1 was successfully carried out in the 5 l scale culture system with the net and a hydrophobic membrane for cell filtration. The viable cell concentration reached 2.7 X 10(7) cells/ml after twenty-seven days, in spite of the nutrient-deficient condition of the lower medium exchange rate, that is, a working volume a day, and viability was maintained at more than 90%. In a 1.21 scale culture of mouse-mouse hybridoma cell STK-1, viable cell concentration reached 4 X 10(7) cells/ml. These results showed that oxygen transfer by gas sparging with defoaming was useful for high density suspension culture. A foam-breaking mechanism was proposed.