A Structure-Relationship Study of the Uptake of Aliphatic Polyamine Compounds by Rat Intestinal Brush-border Membrane Vesicles

The effects of lipophilicity, ion-diffusion potential and membrane surface potential on the uptake of various aliphatic polyamine compounds by rat intestinal brush-border membrane vesicles (BBMV) have been investigated. A valinomycin-induced potassium-diffusion potential (inside-negative) stimulated the initial uptake of diamine compounds, and good correlation was observed between lipophilicity and the amount of diffusion-potential-dependent transport of the diamines. In contrast, because of their much lower lipophilicity, tri- and tetraamine compounds were not affected by the diffusion potential. Tetracaine, which can make the membrane surface potential more positive, inhibited the transport rate of 1,9-nonanediamine, spermidine and spermine by the BBMV. These data suggest that the transport mechanism of diamines is similar to that of monoamine compounds in respect to its dependence on ion-diffusion potential and on the membrane surface potential. The extent of the effect of ion-diffusion potential on the rate of transport of the diamines was closely related to the lipophilicity of the diamine. In contrast, only the surface potential contributed to the transport mechanism of lower lipophilic tri- and tetraamine compounds.     

AP-811, a novel ANP-C receptor selective agonist

AP-811 is a derivative of the Phe8-Ile15 region of atrial natriuretic peptide (ANP) and is one of the smallest linear ligands for ANP receptors. The binding and agonist activities of AP-811 have been compared with those of other ANP analogs for the ANP-A and ANP-C receptors. AP–811 binds with a high binding affinity to and is a strong agonist for the ANP-C receptor, indicating that the binding and agonist sites for this receptor are the same or near each other in the ANP sequence. In contrast, AP-811 showed no agonistic effect for the ANP-A receptor, although it could bind to this receptor. Comparing the biological activities of AP-811 with those of other ANP analogs, we propose that the binding and agonist sites for the ANP-A receptor may consist of separate regions of ANP. In conclusion, AP-811 is the smallest C-receptor-selective agonist.     

个旧市郊室内氡、钍射气浓度和地面γ辐射水平初步调查

目的调查个旧地区居室内氡（^222Rn）、钍射气（^220Rn）及其子体水平，明确钍射气的剂量贡献。方法考虑住宅类型和地理分布因素，从个旧市郊某村选取建筑结构有代表性的50户住宅的主卧室，采用氡-钍射气鉴别探测器测量氡、钍射气浓度，用沉积率装置测量钍射气子体浓度。其中14间居室采用连续性氡测量探测器和α谱氡、钍射气鉴别探测器测量氡、钍射气浓度，空气采样滤膜结合CR-39探测器测量钍射气衰变产物浓度，碘化钠闪烁计数器测量地表γ剂量率。结果50间居室的氡浓度为32～498Bq／m^3，平均136Bq／m^3；钍射气浓度为39～7908Bq／m^3，平均3297Bq／m^3；钍射气子体浓度为2．0～23．9Bq／m^3，平均10．2Bq／m^3。钍射气子体衰变产物致居民年平均有效剂量大于氡子体衰变产物的平均年有效剂量（2．9mSv vs 1．6mSv）。结论个旧市郊部分居室室内钍射气及其子体浓度高，钍射气子体的剂量贡献要高于氡子体的剂量贡献。在个旧开展氡致肺癌危险评价研究应当考虑钍射气子体的剂量贡献。     

Ultra-high-molecular-weight Polyethylene (UHMWPE) Wing Method for Strong Cranioplasty

We developed a new cranioplasty method that utilizes artificial bone made of ultra-high-molecular-weight polyethylene, with a wedge-shaped edge (UHMWPE Wing). This study shows the methods and data of case series and finite element analyses with the UHMWPE Wing. A circumferential wing was preoperatively designed for a custom-made artificial bone made of UHMWPE to achieve high fixed power and to minimize the usage of cranial implants. Here, we present 4 years of follow-up data and finite element analyses for patients treated with the UHMWPE Wing between February 2015 and February 2019. Eighteen consecutive patients underwent cranioplasty using our UHMWPE Wing design. There were no postoperative adverse events in 17 of the patients for at least 18 months. One case of hydrocephalus experienced screw loosening and graft uplift due to shunt malfunction. Placement of a ventriculo-peritoneal shunt immediately returned the artificial bone to normal position. Finite element analyses revealed that a model using the UHMWPE Wing had the highest withstand load and lowest deformation. This is the first report on the UHMWPE Wing method. This method may enable clinicians to minimize dead space and achieve high strength in cranioplasty.     

Ventricular Late Potential in Patients with Apparently Normal Electrocardiogram; Predictor of Brugada Syndrome

Backgrounds: Brugada syndrome can be overlooked due to its dynamic change in its electrocardiogram (ECG) manifestation. We hypothesized that positive ventricular late potential (VLP) in patients with nonspecific ECG would predict the inducible coved ST elevation (type‐1 Brugada ECG) and the patients at high risk. Methods: Thirty‐four patients of nonspecific ECG without structural heart disease were eligible for this study. All patients were referred for evaluation of syncopal episodes and/or cardiac arrest and/or frequent episodes of ventricular premature contractions. We assessed the correlation between baseline VLP and the alteration to a drug‐induced type‐1 Brugada ECG, and also evaluated the diagnostic accuracy of positive VLP in normal ECG subjects for the appearance of a drug‐induced type‐1 Brugada ECG. Results: Twenty‐one patients presented positive VLP and 13 patients showed negative VLP. Parameters of VLP (fQRSd, RMS₄₀, LAS₄₀) presented significant correlation with the alteration to a type‐1 ECG by pilsicainide. VLP demonstrated high sensitivity and negative predictive value for the prediction of type‐1 Brugada ECG. Furthermore, in their follow‐up, at least two cases of ventricular fibrillation were recognized in 21 of positive VLP patients with apparently normal ECGs. Conclusions: VLP in apparently normal ECG can predict the alteration to a drug‐induced type‐1 Brugada ECG and unmask the patients at risk. (PACE 2010; 33:266–273)     

A Randomized Comparison of the Straight Linear Approach with Electrogram Mapping Focal Approach in Selective Slow Pathway Ablation

HAYASHI, M., et al. : A Randomized Comparison of the Straight Linear Approach with Electrogram Mapping Focal Approach in Selective Slow Pathway Ablation. The aim of this study was to evaluate the efficacy and safety of the anatomic linear approach in selective AVN slow pathway ablation, in comparison to the widely used electrogram mapping focal approach. It remains undetermined whether or not anatomic linear ablation has a greater potential for eliminating slow pathway conduction than does focal ablation. Fifty consecutive patients (21 men, 29 women, age  56 ± 14  years) with common type AVNRT were randomly assigned to the linear approach (25 patients) or local electrogram mapping approach (25 patients). A linear lesion was created between the tricuspid annulus, at the midlevel of the coronary sinus (CS) ostium, and the anterior aspect of the CS infundibulum. In 22 (88%) patients in the linear group, the AVNRT was successfully eliminated by  1.5 ± 0.8  linear RF applications without any complications. All 25 patients in the focal group satisfied the endpoint criteria after  3.8 ± 2.4  focal RF deliveries. The success rate did not significantly differ between the two groups. Out of the 22 patients with a successful outcome in the linear group, 17 (77%) attained complete abolition of the slow pathway conduction, whereas this was observed in only eight (32%) patients in the focal group (  P < 0.005  ). The session time was significantly shorter in the linear group. Recurrence of the tachycardia was not documented in any patient during a mean follow-up of  18 ± 8  months except one with residual slow pathway conduction in the focal ablation group. In conclusion, the anatomic linear approach can be performed safely and possesses a greater potential for slow pathway interruption compared to the electrogram mapping focal approach.     

羟基积雪草苷对转基因肌萎缩侧索硬化小鼠的治疗作用

目的探讨羟基积雪草苷对铜锌超氧化物歧化酶(Cu,Zn superox ide d ism u tase,SOD 1)-G 93A突变肌萎缩侧索硬化(am yotroph ic latera l scleros is,ALS)小鼠的治疗作用。方法通过行为学和组织学测定,观察羟基积雪草苷对SOD 1-G 93A突变ALS小鼠发病时间、生存时间、运动功能变化和神经元病理改变的影响。结果羟基积雪草苷(61.1±11.0)和(185.6±18.7)m g/(kg.d)在小鼠日龄70 d时开始给药至死亡,能分别延长SOD 1-G 93A突变ALS小鼠的生存时间11.4和9.4 d,但对发病时间无影响;同时(61.1±11.0)m g/(kg.d)组小鼠在肌力缓慢下降期运动功能降低减缓,与对照组比较差异显著(P<0.05)。120 d时L 2~5组织切片显示两治疗组脊髓前角运动神经元数明显高于SOD 1-G 93A对照组(P<0.05),多数运动神经元胞浆中仍有尼氏体存在。结论羟基积雪草苷对SOD 1-G 93A突变转基因小鼠运动神经元变性有保护作用,能延长小鼠的生存时间。