±Genetic structure of the oak wilt vector beetle Platypus quercivorus: inferences toward the process of damaged area expansion

<p>Abstract</p> <p>Background</p> <p>The ambrosia beetle, <it>Platypus quercivorus</it>, is the vector of oak wilt, one of the most serious forest diseases in Japan. Population genetics approaches have made great progress toward studying the population dynamics of pests, especially for estimating dispersal. Knowledge of the genetic structuring of the beetle populations should reveal their population history. Using five highly polymorphic microsatellite loci, 605 individuals from 14 sampling sites were assessed to infer the ongoing gene flow among populations as well as the processes of expansion of damaged areas.</p> <p>Results</p> <p>Population differentiation (<it>F</it>_ST= 0.047, <it>G'</it>_ST= 0.167) was moderate and two major clusters were detected by several methods, dividing the samples into north-eastern and south-western populations, a similar genetic divergence was reported in host oak trees. Within the north-eastern populations, the subgroups mostly corresponded to differences in the collection period. The genetic characteristics of the population might have changed after 2 years due to the mixing of individuals between populations with enhanced migration related to population outbreaks. Because isolation by distance was detected for whole populations and also within the north-eastern populations, migration was considered to be limited between neighbouring populations, and most populations were suggested to be in genetic equilibrium of genetic drift and gene flow. Recent bottlenecks were found in some populations with no geographical bias; however, they were all from newly emerged oak wilt forests. The emergence of oak wilt should have induced intense fluctuations in the beetle population size.</p> <p>Conclusions</p> <p>Because the genetic boundaries coincide, we suggest that the geographical structuring of the beetle was formed by co-evolution with the host species. Our findings indicate the oak wilt expansion process.</p

複雑先天性心疾患患者における心房細動の病因 : より良い治療戦略のために

Background: The demographics of patients with congenital heart disease (CHD) and atrial fibrillation (AF) differ significantly from the general population. The etiology and treatment strategy for AF in CHD patients have been investigated but are to date inconclusive. Methods: To determine the etiology of AF in CHD and to seek a better treatment strategy, we retrospectively evaluated the atrial overload in 42 complex CHD cases with normal atrial arrangements and AF (age 25; range, 9-66 years) and the impact of a reduction in the atrial overload on the atrial rhythm. Results: Cardiac defect diagnoses varied, with 17% of the patients having a persistent left superior vena cava (PLSVC). In regard to the volume overload, the frequencies of an overload in the right atrium (RA), left atrium (LA), or both, were 50 %, 23%, and 10%, respectively (p = 0.015). Other sustained supraventricular tachycardias were observed in 29 patients (69%) before and after the onset of AF. Among these 29 patients, 26 had intra-atrial reentrant tachycardia. Fifteen patients (36%), 10 of whom had chronic AF, died during the follow-up including 3 with arrhythmias and 10 because of heart failure. Fourteen (33%) patients had no AF at the last follow-up due to medical interventions, 8 of which underwent solely an RA-sided catheter ablation and/or surgical RA overload reduction. Conclusions: AF in complex CHD with a normal atrial arrangement correlates with a higher RA-sided overload than an LA-sided and exhibits a high incidence of PLSVCs, high comorbidity of intra-atrial reentrant tachycardias, and high mortality rate. In a substantial number of patients, RA-sided interventions were effective in controlling AF. To effectively manage AF in complex CHD it is essential to understand each individual's hemodynamics and consider hemodynamic interventions.博士（医学）・甲第853号・令和4年9月28日© 2020 Published by Elsevier Ltd on behalf of Japanese College of Cardiology

Significance of Coronary Revascularization for Coronary-Artery Obstructive Lesions Due to Kawasaki Disease

As an acquired ischemic heart disease in childhood, coronary-artery disease caused by Kawasaki disease (KD) has been known worldwide since the mid-1970s. KD patients who develop coronary-artery obstructive disease often need revascularization some time in their life. Coronary-artery revascularization for KD coronary lesions can be done with the surgical coronary-artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) procedures. However, the characteristics of coronary-arterial lesions caused by KD significantly differ from atherosclerotic coronary disease in adults. Therefore, it is much more difficult to determine the optimal time and selection of a coronary-artery revascularization procedure for KD sequelae. CABG using the internal thoracic artery has been accepted as a very useful and beneficial procedure since the mid-1980s, even in small children. Although the use of PCI in the late period can be effective in some adolescent and adult patients, the small vessel size and severe coronary-artery calcification are often limiting factors for its use in children. Therefore, CABG is a better approach for severe leftanterior descending artery and multiple-vessel disease in children and adolescents with KD coronary sequelae. Good coronary revascularization can improve the long-term outcomes of patients with severe KD complications