Image reconstruction of anisotropic conductivity tensor distribution in MREIT: computer simulation study

We describe a novel method of reconstructing images of an anisotropic conductivity tensor distribution inside an electrically conducting subject in magnetic resonance electrical impedance tomography (MREIT). MREIT is a recent medical imaging technique combining electrical impedance tomography (EIT) and magnetic resonance imaging (MRI) to produce conductivity images with improved spatial resolution and accuracy. In MREIT, we inject electrical current into the subject through surface electrodes and measure the z-component Bz of the induced magnetic flux density using an MRI scanner. Here, we assume that z is the direction of the main magnetic field of the MRI scanner. Considering the fact that most biological tissues are known to have anisotropic conductivity values, the primary goal of MREIT should be the imaging of an anisotropic conductivity tensor distribution. However, up to now, all MREIT techniques have assumed an isotropic conductivity distribution in the image reconstruction problem to simplify the underlying mathematical theory. In this paper, we firstly formulate a new image reconstruction method of an anisotropic conductivity tensor distribution. We use the relationship between multiple injection currents and the corresponding induced Bz data. Simulation results show that the algorithm can successfully reconstruct images of anisotropic conductivity tensor distributions. While the results show the feasibility of the method, they also suggest a more careful design of data collection methods and data processing techniques compared with isotropic conductivity imaging.     

葛根素对降低2型糖尿病患者微量白蛋白尿的临床观察

目的：观察葛根素对2型糖尿病早期肾脏病变的疗效。方法：对73例2型糖尿病24h尿微量白蛋白（UAE）在30－300mg/24h者随机分成两组,治疗组37例,每天静滴葛根素500mg,共2周;对照组用生理盐水静滴,共2周。观察血糖及尿UAE变化。结果：两组治疗前后比较差异有显著性意义,P＜0．01。结论：葛根素对2型糖尿病早期肾脏病变疗效明显,且无明显毒副反应。     

急性乙状结肠扭转行纤维结肠镜复位体会（附二例报道）

目的 介绍急性乙状结肠扭转行纤维结肠镜复位治疗操作方法及注意事项。方法 采用国产CS－120型纤维结肠镜对二例急性乙状结肠扭转病人进行检查复位。结果 急性乙状结肠扭转病人可通过非手术治疗方法即行纤维结肠镜检查复位获得成功。结论 纤维结肠镜操作简单、成功率高,不失为非手术治疗乙状结肠急性扭转的首选方法。     

早期食管癌的病理形态观察及组织发生学探讨

目的探讨早期食管癌的组织发生学.方法对109例早期食管癌及癌周病变进行病理观察.结果其中20例的一点癌(黄豆大小),3例双原发癌,1例小细胞癌.癌周伴有不同程度的鳞状上皮异形增生和不典型增生.结论早期食管具有多样性生长的特点.提示临床医生在胃镜检查应注意多点取材,以防漏诊;以及正确确定手术范围,防止手术残留.     

云南个旧和宣威地区肺癌p53突变检测研究

目的　云南个旧及宣威地区是云南省肺癌的两大点状高发区 ,个旧以矿工为高发人群 ,宣威以农民为高发 ,该两地区肺癌发生的病因已初步阐明 ,本研究旨在深入探讨其发病的分子生物学基础。方法　对 2 6例个旧矿工肺癌患者 ,15例宣威农民肺癌患者 ,应用聚合酶链反应 -单链构象多态性法研究 p5 3第 5至第 8外显子突变 ,并对有突变的个体进行测序。结果　发现云锡矿工肺癌患者中有 13例、宣威农民肺癌患者中有 4例发生 p5 3突变 ,应用 DNA测序 ,发现云锡矿工肺癌中有 1例于第 135位密码子发生突变 ,由 GCC→ GTC,导致氨基酸改变 ,由丙氨酸→缬氨酸 (Ala→ Val) ,宣威农民肺癌患者中有 1例于 2 47位密码子突变 ,由 AAC→ TTC,导致氨基酸发生改变 ,由天冬酰氨→苯丙氨酸 (Asn→ Phe)。结论　 p5 3突变在云锡矿工肺癌和宣威农民肺癌中较常发生 ,并发现两例新的突变位点。 p5 3突变与病人的年龄、性别、坑龄及组织学分类无明显联系     

Outcomes and factors associated with early mortality in pediatric postcardiotomy veno‐arterial extracorporeal membrane oxygenation

Mortality and morbidity of children received veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) support after cardiac surgery remain high despite remarkable advances in medical management and devices. The purpose of this study was to describe outcomes and risk factors of applying VA‐ECMO in the surgical pediatric population. We retrospectively analyzed 85 consecutive pediatric patients (aged <18 years) who received postcardiotomy VA‐ECMO from January 2010 to December 2018. Median (IQR) age at ECMO implantation in this cohort was 12.7 (6.4, 43.2) months, median weight was 8.5 (6.0, 12.8) kg, mean ECMO duration was 143.2 ± 81.6 hours and mean hospital length of stay was 48.4 ± 32.4 days. Seventy‐five patients (88.2%) were indicated for postcardiotomy cardiogenic shock. The successful ECMO weaning rate was 70.6% and in‐hospital mortality was 52.9%. The most common diagnosis was transposition of great arteries (n = 18, 21.2%), while acute kidney injury occurred most often (n = 64, 75.3%). Multivariate logistic regression analysis showed that thrombocytopenia, hemolysis, and nosocomial infection were positively correlated with in‐hospital mortality. Multivariate Cox proportional hazard regression analysis presented that thrombocytopenia significantly increased the 180‐day mortality in patients with successful weaning. Therefore, multiple factors had adverse effects on prognosis. Patient selection and procedures from ECMO implantation to weaning need to be closely monitored and performed in a timely manner to improve outcome.     

Long-term mortality of living kidney donors: a systematic review and meta-analysis

International Urology and Nephrology - To date, several studies have reported inconsistent findings regarding the mortality risk faced by living kidney donors and controls. Our study assessed the...     

Central Regulation of Branched-Chain Amino Acids Is Mediated by AgRP Neurons

Circulating branched-chain amino acids (BCAAs) are elevated in obesity and diabetes, and recent studies support a causal role for BCAAs in insulin resistance and defective glycemic control. The physiological mechanisms underlying BCAA regulation are poorly understood. Here we show that insulin signaling in the mediobasal hypothalamus (MBH) of rats is mandatory for lowering plasma BCAAs, most probably by inducing hepatic BCAA catabolism. Insulin receptor deletion only in agouti-related protein (AgRP)–expressing neurons (AgRP neurons) in the MBH impaired hepatic BCAA breakdown and suppression of plasma BCAAs during hyperinsulinemic clamps in mice. In support of this, chemogenetic stimulation of AgRP neurons in the absence of food significantly raised plasma BCAAs and impaired hepatic BCAA degradation. A prolonged fasting or ghrelin treatment recapitulated designer receptors exclusively activated by designer drugs–induced activation of AgRP neurons and increased plasma BCAAs. Acute stimulation of vagal motor neurons in the dorsal motor nucleus was sufficient to decrease plasma BCAAs. Notably, elevated plasma BCAAs were associated with impaired glucose homeostasis. These findings suggest a critical role of insulin signaling in AgRP neurons for BCAA regulation and raise the possibility that this control may be mediated primarily via vagal outflow. Furthermore, our results provide an opportunity to closely examine the potential mechanistic link between central nervous system–driven BCAA control and glucose homeostasis.