Objective. We investigated whether the aging-related decrease in gap junction expression affects myocardial response against ischemia-reperfusion injury of the rabbit myocardium. Methods. Isolated aged (≥135 weeks) or mature (15-20 weeks) rabbit hearts were perfused with Krebs-Henseleit solution via a Langendorff apparatus, and were divided into five groups as follows: 7 mature hearts served as mature controls (Group A), 7 mature hearts underwent ischemic preconditioning (IPC) consisting of two cycles of global ischemia for 5min followed by reperfusion for 5min (Group B), 7 aged hearts served as aged control (Group C), 7 aged hearts underwent IPC (Group D) and 7 mature hearts received 1mM of gap junction uncoupler heptanol for 5min (Group E). Then, all hearts were subjected to 1h of left anterior descending coronary artery occlusion followed by 1h of reperfusion. Left ventricular pressure, ischemic zone monophasic action potential and coronary flow were measured throughout the experiment and the infarct size (IS) was determined at the end of the experiment. Gap junction expression was investigated by the electron microscopy. Results. The IS of Group A was 39.1±3.8 (%) and that of Group B was 26.9±3.8 (%)^* (^*p<0.05 vs. Group A). The IS of Group C was 19.3± 1.6(%)^*. That of Group D was 43.6±5.8 (%)^# (^#p<0.05 vs. Group C). IS of Group E was 24.3±1.6 (%)^*. Electron microscopic findings demonstrated that gap junction expression in aged hearts was less prominent than in mature ones. Conclusion. These data suggested that aged myocardium might be more tolerant of ischemic insult than that of mature heart, and that the mechanism might be related to the aging-related change of gap junction expression.

A survey was carried out on how the To-no District is coping with the need of first aid for patients requiring life-supporting treatment before hospitalization. Although there were cities in this district where statistics on first aid were not available, the survey found that, during the 4-year period from 1994 through 1997, bystander CPR (cardiopulmonary resuscitation) saved 11.2% of the lives of patients with CPA (cardiopulmonary arrest). Incidentally, 11.3% of the population attended CPR courses offered by public institutions. Gifu Prefecture has helicopters for use in rescue work, but the survey found that some cities had not ever sponsored drills using helicopters in life-saving operations. Our findings revealed the indifference of the general public as well as administrators in this district toward emergency care. Public recognition of the importance of the care of suddenly ill or injured patients must be gained. Furthermore, acquisition of skills required for first aid by lay people and technical improvement of these skills in professional rescuers are necessary. The authors think that these are the community educational responsibility of hospitals and other medical institutions.

Background: Rotavirus vaccines were introduced in Japan in November 2011. We evaluated the subsequent reduction of the health-care burden of rotavirus gastroenteritis. Methods: We conducted active surveillance for rotavirus gastroenteritis among children under 5 years old before and after the vaccine introduction. We surveyed hospitalization rates for rotavirus gastroenteritis in children in Tsu City, Mie Prefecture, Japan, from 2007 to 2015 and surveyed the number of outpatient visits at a Tsu City clinic from 2010 to 2015. Stool samples were obtained for rotavirus testing and genotype investigation. We assessed rotavirus vaccine coverage for infants living in Tsu City. Results: In the pre-vaccine years (2007-2011), hospitalization rates for rotavirus gastroenteritis in children under 5 years old were 5.5, 4.3, 3.1 and 3.9 cases per 1000 person-years, respectively. In the post-vaccine years (2011-2015), the rates were 3.0, 3.5, 0.8 and 0.6 cases per 1000 person-years, respectively. The hospitalization rate decreased significantly in the 2013-2014 and 2014-2015 seasons compared to the average of the seasons before vaccine introduction (p < 0.0001). In one pre-vaccine year (2010-2011), the number of outpatient visits due to the rotavirus infection was 66. In the post-vaccine years (2011-2015), the numbers for each season was 23, 23, 7 and 5, respectively. The most dominant rotavirus genotype shifted from G3P[8] to G1P[8] and to G2P[4]. The coverage of one dose of rotavirus vaccine in Tsu City was 56.5% in 2014. Conclusion: After the vaccine introduction, the hospitalization rates and outpatient visits for rotavirus gastroenteritis greatly decreased.