Keiichiro Kato

Antiviral activity of NMSO3 against adenovirus in vitro

NMSO3, a sulfated sialyl lipid, was evaluated for its efficacy against adenovirus (AdV) in vitro. The median effective concentration (50% effective concentration, EC(50)) of NMSO3 against replication of AdV type 2 (AdV2), type 4 (AdV4), type 8 (AdV8) and type 37 (AdV37) was 0.21-0.71 microg/ml in HEp-2 cells and 1.01-1.41 microg/ml in MKN-28 cells. The EC(50) values of NMSO3 were lower than those of HPMPC and ddC, which were also evaluated. NMSO3 exhibited minimal cytotoxicity against HEp-2 cells and MKN-28 cells, both for which the median cytotoxic concentration (50% cytotoxic concentration, CC(50)) was more than 1000 microg/ml. NMSO3 was the most potent and selective anti-AdV compound of those examined. NMSO3 inhibited AdV infection of HEp-2 cells only when present during the virus adsorption period. A virus binding assay using radiolabeled AdV4 revealed that NMSO3 inhibited viral binding to the HEp-2 cells. NMSO3 itself bound to the virus particles, but not to the HEp-2 cell membrane. Thus, the mechanism of anti-AdV activity by NMSO3 involves inhibition of virus adsorption to cells by NMSO3 binding to viral particles.

Measuring Accommodation Time with a Laptop Computer

PurposePresently, there are no completely reliable examinations such as focus from a distant place to a near place during daily work. We developed a simple testing system for accommodation time using a 5 m chart and a laptop computer.Material and MethodsWe studied 177 healthy subjects. They turned their eyes from the 5 m chart to the display of the personal computer at about 70 cm in front of the eyes. We measured the minimum time (MTC) for recognizing three Kanji (Chinese characters) randomly chosen from a total of 15 characters on the display.ResultThe MTCs with +1.25 D added were shorter than those with complete correction. The MTCs in both conditions extended with age. In subjects less than 40 years old, the MTCs measured with both eyes were significantly shorter than those with a single eye completely corrected. In subjects over 40 years old, there was no difference. The MTCs were shorter significantly with complete correction than with +1.25 D added. The MTCs decreased as the accommodative amplitude increased.ConclusionsThere is significant correlation between the accommodative amplitude and the MTCs. We can use the MTCs as one method of measuring time of accommodation. Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc 107:380–387, 2003)

VDT Work and Refraction of Junior High School Students

Although visual display terminal (VDT) work has increased through compulsory education, sufficient investigation has not been conducted regarding tar function of young people. Computer Science Summer Camp ’97 was held for 4 day and 3 nights at Aizu University in Fukushima in 1997. One hundred junior high school students participated in the camp and performed VDT work for about 16 hours in 4 day, We surveyed the refractive changes and subjective symptoms in the participants before and after VDT work. Theaverage refractive change was −0.02 ± 0.46D. The change was not significant. The average refractive changes in myopia, byperopia and emmetripia were −0.11 ± 0.43D, −0.06 ± 0.22D and −0.24 ± 0.56D, respectively. Many participants (51.6%) demonstrated eye fatigue. Significant change in refraction was observed in the myopic direction in emmetripia. This tendency was clearer in the participants who exhibited marked eye fatigue.

Detection of resting state of accommodation by accommodative microfluctuation

Accommodative microfluctuations were recorded when the subjects were looking at a stable target. The waves of the accommodative microfluctuation were analyzed by fast Fourier transform. When accommodation was in a resting state, the high frequency components were minimized. This suggested that the resting state of accommodation might be measured when the subject was looking at a target. At a little distance from the resting state of accommodation, the high frequency components were maximized. This might suggest a negative accommodation.