Effects of the Prophylactic Use of Amiodarone Infusion to Prevent Postoperative Atrial Fibrillation after Cardiac Surgery

Postoperative atrial fibrillation（AF）is associated with significant morbidity after cardiac surgery. We examined the effects of a prophylactic postoperative amiodarone infusion to prevent postoperative AF. A prospective randomized study was performed in patients with a high risk of postoperative AF between March 2016 and March 2019. High risk of AF was defined as combined valve surgery, aortic valve replacement（age＞70）, or off-pump coronary bypass grafting（age＞65）. Forty-two patients were enrolled and randomly assigned to receive prophylactic amiodarone infusion（amiodarone group, n＝20）or saline infusion（control group, n＝22）. In the amiodarone group, amiodarone was infused intravenously for 48hr postoperatively（initially 125mg/10min, then 288mg/6hr, then maintenance of 1,040mg/42hr）. There were no significant differences between the two groups in age, sex, body height, body weight, surgical procedure, and perioperative use of beta blockers. The occurrence of sustained AF for＞1hr was significantly lower in the amiodarone group（30.0％）than in the control group（63.6％, p＝0.04）. The total duration of AF over one week was also significantly shorter in the amiodarone group（296.8±676.9min）than in the control group（921.4±1641.6min, p＝0.04）, as was the postoperative hospital stay（17.3±6.1 vs. 24.5±11.3 days, respectively, p＝0.01）. There were no major side effects with amiodarone infusion except for one case of bradycardia. These results show the prophylactic use of intravenous amiodarone infusion for the first 48hr of the postoperative period is a safe and effective treatment to prevent postoperative AF after cardiac surgery and to shorten the hospital stay

Eicosapentaenoic Acid Suppresses the Proliferation of Synoviocytes from Rheumatoid Arthritis

Eicosapentaenoic acid (EPA) is essential for normal cell growth, and may play an important role in inflammatory and autoimmune disorders including rheumatoid arthritis. We investigate that EPA could suppress the proliferation of fibroblast like synoviocytes in vitro. We treated synoviocytes with 1 to 50 µM EPA and measured cell viabilities by the modified MTT assay. We sorted the number of them in sub G1 stage by fluorescence-activated cell sorting caliber. And we stained them by light green or Hoechst 33258, and investigate microscopic appearance. The cell viabilities were decreased at 30 µM, 40 µM, and 50 µM of EPA comparing to 0 µM of EPA. The half maximal concentration of synoviocytes inhibition was approximately 25 µM. At day 1 and day 3, cell number was also decreased at 50 µM EPA comparing to control. FACS caliber indicated the number of synoviocytes in sub G1 stage did not increase in each concentration of EPA. Hoechst staining indicated normal chromatin pattern and no change in a nuclear morphology both in EPA treated synoviocytes and in untreated synoviocytes. These findings suggest that EPA could suppress the proliferation of synoviocytes in vivo dose dependently and time dependently, however, the mechanism is not due to apoptosis

Ecological traits and their diversities of five Zostera marina populations in and around Hiroshima Bay, the Seto Inland Sea, Japan

広島湾および周辺海域の5カ所の生育地のアマモZostera marinaの生態的特性を2004年の繁茂期に調査した。調査場所は広島湾奥部の阿品（St.1），同湾央部の大黒神島（St.2），同湾口部の屋代島（St.3），柳井湾奥部の伊保庄（St.4），および同湾外部に位置する平郡島（St.5）である。アマモの分布水深は生育地により異なり，St.1，St.2では海底でのアオサ類等の堆積により，分布下限水深は1-2m（C.D.L. 基準）までである一方，他の生育地では4-6mまで分布した。アマモの平均現存量は120-180g DWm-2の範囲にあったが，アマモの株のサイズと密度は生育地により異なっていた。平均株密度は生育地により88-278 shoots m-2の範囲であり，St.3およびSt.5では特に浅所で小型の株が密生した。これらの群落では，総現存量に占める地下部現存量の割合が相対的に大きかった。一方，湾奥部に位置するSt.1とSt.4では，アマモの株は大型である一方生育密度は低かった。群落内の底質の粒度組成の相違から，波浪流動等の物理的環境が生育地間で異なることが示唆され，それぞれの場所のアマモの生態的特性はその影響を受けていると考えられた。Ecological traits of five Zostera marina populations in and around Hiroshima Bay were investigated in a luxuriant season of 2004. Study sites were located at the most inner (Ajina; St.1), center (O-kurokami-jima; St. 2) and near the mouth area (northern coast of Yahiro-jima; St. 3) of Hiroshima Bay, and at the inner area (Ihono-sho; St. 4) and the outside (Heigun-jima; St.5) of Yanai Bay which is the strait adjacent to Hiroshima Bay. The distribution depth (C.D.L.) was different among the populations. The lower depth of Zostera distribution was limited to 1-2 m at St.1 and 2 by algal-mat of Ulva spp. and other macroalgae, though it was 4-6 m at St. 3-5. Mean biomass was ranged in 120-180g DWm-2, but shoot size and density was different among the populations. Mean density ranged between 88-278 shoots m-2, and the populations at St.3 and 5 exhibited higher densities with smaller shoots especially in shallow stands of the two population. These stands also exhibited higher proportion of below-ground biomass to total biomass. On the contrary, populations in inner areas (St. 1 and 4) exhibited lower density with larger shoots. Physical conditions such as water motion induced by waves were different among the habitats which were shown in grain size compositions of the sediments, and this could affect the ecological traits of each Z. marina population.本調査は，水産庁委託「生物多様性に配慮したアマモ場造成技術開発調査事業」（平成16～18年度）の一環として実施されたものである

Bispectral index-guided propofol sedation during endoscopic ultrasonography

Background/Aims Bispectral index (BIS) monitors process and display electroencephalographic data are used to assess the depth of anesthesia. This study retrospectively evaluated the usefulness of BIS monitoring during endoscopic ultrasonography (EUS). Methods This study included 725 consecutive patients who underwent EUS under sedation with propofol. BIS monitoring was used in 364 patients and was not used in 361. The following parameters were evaluated: (1) median dose of propofol; (2) respiratory and circulatory depression; (3) occurrence of body movements; (4) awakening score >8 at the time; and (5) awakening score 2 hours after leaving the endoscopy room. Results The BIS group received a significantly lower median dose of propofol than the non-BIS group (159.2 mg vs. 167.5 mg; p=0.015) in all age groups. For patients aged ≥75 years, the reduction in heart rate was significantly lower in the BIS group than in the non-BIS group (1.2% vs. 9.1%; p=0.023). Moreover, the occurrence of body movements was markedly lower in the BIS group than in the non-BIS group (8.5% vs. 39.4%; p<0.001). Conclusions During EUS examination, BIS monitoring is useful for maintaining a constant depth of anesthesia, especially in patients 75 years of age or older

The history of human populations in the Japanese Archipelago inferred from genome-wide SNP data with a special reference to the Ainu and the Ryukyuan populations

The Japanese Archipelago stretches over 4000 km from north to south, and is the homeland of the three human populations; the Ainu, the Mainland Japanese and the Ryukyuan. The archeological evidence of human residence on this Archipelago goes back to 430 000 years, and various migration routes and root populations have been proposed. Here, we determined close to one million single-nucleotide polymorphisms (SNPs) for the Ainu and the Ryukyuan, and compared these with existing data sets. This is the first report of these genome-wide SNP data. Major findings are: (1) Recent admixture with the Mainland Japanese was observed for more than one third of the Ainu individuals from principal component analysis and frappe analyses; (2) The Ainu population seems to have experienced admixture with another population, and a combination of two types of admixtures is the unique characteristics of this population; (3) The Ainu and the Ryukyuan are tightly clustered with 100% bootstrap probability followed by the Mainland Japanese in the phylogenetic trees of East Eurasian populations. These results clearly support the dual structure model on the Japanese Archipelago populations, though the origins of the Jomon and the Yayoi people still remain to be solved

Mulching Effects and the Soil Organic Matter Dynamics in Crushed Bamboo Utilization at the Farmland

The objective of this research was to evaluate the effect of covering the soil surface with the crushed bamboo and to simulate the soil organic matter dynamics after the crushed bamboo was put into the soil a farmland. The first experiments in the phytotron (25 ?C, 70%) showed that covering the soil with the 2 cm and 4 cm thick crushed bamboo prevented the decrease of the soil water content as well as vinyl mulching. and reduced the total amount of the irrigated water 20% less than no mulching. In addition, the crushed bamboo mulching kept the soil temperature lower than the others and made the electrical conductivity in the soil high just after irrigation. The second experiment showed that the crushed bamboo mulching applied the potassium to the crown daises so that the potassium content of the crown daises increased. Finally, the soil organic matter dynamics was simulated with the CENTURY model. It was predicted that if the 2 cm thick crushed bamboo was put into the soil, the most was decomposed in 20 years, and when it was put into the soil every year, the total amount of the soil organic carbon increased 7000 g/m2 in 20 years, which made the C: N ratio keep 20. In this simulation, it seemed that the crushed bamboo of which thickness was less than 2 cm can be applied