Evaluation of corneal damage caused by the anticancer drug S-1 in human corneal epithelial cells

The combination drug S-1, which contains tegafur, gimeracil, and oteracil potassium, is a fluoropyrimidine-based oral antineoplastic agent in which the principal drug tegafur is a prodrug of fluorouracil （5-FU）. In recent years, many studies have reported eye problems, especially corneal damage, as an adverse effect of S-1 treatment. In this study, we investigated the cytotoxic effects of each of the constituents of S-1 on corneal epithelial cells by measuring viable cell counts and lactate dehydrogenase （LDH） release. Experimental chemosensitivity study for 5-FU and the constituents of S-1 （i.e., tegafur, gimeracil, and oteracil） using a human cell line. We used immortalized human corneal epithelial （HCE-T） cells to estimate viable cell counts （expressed as a percentage of the control cells） and the activity of LDH in a culture medium （expressed as a percentage of the total LDH activity）. Decreases in viable cell counts were noted with 5-FU and tegafur, but a significant elevation in LDH activity was noted only with tegafur. The incidence of damage in cells exposed to tegafur significantly decreased on adding tranylcypromine, an inhibitor of CYP2A6 that metabolizes tegafur to 5-FU. In addition, 5-FU did not elevate LDH activity, which is an indicator of cell membrane disruption, and concentration-dependence was not observed when cells were treated with 5-FU doses of up to 1,000ng/ml. These findings suggest that the disruption of the metabolic activity of the corneal epithelium by 5-FU is involved in the corneal injury mechanism of S-1

Deep-vein thrombosis detection rates and consideration of the living environment in a tsunami disaster area during the disaster reconstruction phase: A cross-sectional study

Introduction: Tsunami victims of the Great East Japan Earthquake were screened for deep-vein thrombosis(DVT) in order to compare the DVT incidence rates between temporary and non-temporary housing residentgroups. Material and methods: Lower extremity venous ultrasonography was performed on 290 subjects (64 menand 226 women; mean age = 71.9 ± 7.9 years) at 44 months after the disaster. All subjects completedquestionnaires to gather information about their background factors which included the Kessler PsychologicalDistress Scale: K6. Results: The DVT detection rate was 10.7% in the temporary group. In the non-temporary group, it was 11.3%among the subjects who previously lived in temporary housing. For the subjects who were living in their own homes it was 9.2%. Psychological distress levels measured by K6 were significantly higher in the temporary housinggroup than in the non-temporary housing group. The multivariate analysis showed that the background factorassociated with DVT risk was SV (soleal vein) dilatation in all subjects as well as in the non-temporary housinggroup, while hypertension and use of sleeping pills were found to be the factors in the temporary housing group. Conclusions: DVT detection rates were similar between the temporary and non-temporary housing groups,and were higher than that in the Japanese general population. The psychological distress level of the tsunamivictims measured by K6 was also higher in the temporary housing group than in the non-temporary housinggroup. It is necessary to establish a long-term and awareness-raising disaster victim support system

Pandemic Influenza Virus Surveillance, Izu-Oshima Island, Japan

A population-based influenza surveillance study (using PCR virus subtyping) on Izu-Oshima Island, Japan, found that the cumulative incidence of influenza A(H1N1)pdm09 virus infections 2 seasons after the pandemic was highest for those 10–14 years of age (43.1%). No postpandemic A(H1N1)pdm09 case-patients had been infected with A(H1N1)pdm09 virus during the pandemic season

Development of the Aortic Baroreflex in Microgravity

Baroreceptors sense pressure in blood vessels and send this information to the brain. The primary baroreceptors are located in the main blood vessel leaving the heart (the aorta) and in the arteries in the neck (the carotid arteries). The brain uses information from the baroreceptors to determine whether blood pressure should be raised or lowered. These reflex responses are called baroreflexes. Changing position within a gravity field (i.e., moving from lying to sitting or standing) powerfully stimulates the baroreflexes. In weightlessness, the amount of stimuli that the baroreflexes receive is dramatically reduced. If this reduction occurs when the pathways that control the baroreflexes are being formed, it is possible that either the structure or function of the baroreceptors may be permanently changed. To study the effect of microgravity on structural and functional development of the aortic baroreflex system, we studied young rats (eight days old at launch) that flew on the Space Shuttle Columbia for 16 days. Six rats were studied on landing day; another six were studied after re-adapting to Earth's gravity for 30 days. On both landing day and 30 days after landing, we tested the sensitivity of the rats' baroreflex response. While the rats were anaesthetized, we recorded their arterial pressure, heart rate, and aortic nerve activity. After the tissues were preserved with perfusion fixation, we also examined the baroreflex structures. On landing day, we found that, compared to the controls, the flight rats had: fewer unmyelinated nerve fibers in their aortic nerves lower baroreflex sensitivity significantly lower contraction ability and wall tension of the aorta a reduced number of smooth muscle cells in the aorta. In the 30-day recovery group, the sensitivity of the baroreflex showed no difference between the flight rats and the control groups, although the unmyelinated fibers of the aortic nerve remained reduced in the flight rats. The results show that spaceflight does affect the development of the aortic baroreflex. The sensitivity of the reflex may be suppressed; however, the function of the blood pressure control system can re-adapt to Earth's gravity if the rats return before maturation. The structural differences in the input pathway of the reflex (Le., the reduction in nerve fibers) may remain permanently