Role of the transient outward current (Ito) in shaping canine ventricular action potential – a dynamic clamp study

Transmural electrical dispersion determines the repolarization sequence across the ventricular wall, and plays an important role in the development of arrhythmias under pathological conditions. While it is clear that the transmural gradient of the transient outward current ( I _to) underlies the dramatic difference in phase 1 repolarization across the ventricle, its contribution to the transmural action potential duration (APD) dispersion is not clear. We investigated this problem using the dynamic clamp technique in canine ventricular myocytes. The dynamic clamp allows quantitative 'insertion' of simulated conductances in real, biological cells, bridging pure computer modelling and experimental electrophysiology. 'Insertion' of an epicardial level of I _to in endocardial cells produced a prominent phase 1 repolarization and a 'spike-and-dome' action potential morphology, but did not significantly affect the APD. Increasingly larger I _to densities prolonged, and then dramatically shortened the endocardial APD. We also used the dynamic clamp to subtract, or 'block' the native I _to in epicardial cells. Such 'blockade' eliminated the epicardial action potential notch, but had no significant effect on the APD. We conclude that I _to, while being a key regulator of phase 1 repolarization, does not significantly affect the APD of canine ventricular myocytes, and that the I _to gradient is not a significant contributor to the transmural APD dispersion in the canine ventricle. By allowing computer simulation on a biological background, the dynamic clamp is a new and effective tool to study the ionic basis of the electrical properties of cardiac cells.     

腔内激光治疗大隐静脉曲张192例报告

目的 探讨腔内激光治疗大隐静脉曲张的疗效。方法 2004年7月～2006年3月我院对192例238条肢体大隐静脉曲张行高位结扎、激光烧灼静脉主干和小腿曲张静脉。小腿局部严重曲张的静脉团,另做切口做局部切除或点状抽拨。结果 本组一次治愈率96.2%（229/238）。9例9条肢体术后因仍有少量曲张静脉存在,局麻下行切除或再次激光治愈。114例大隐静脉主干及小腿局部条索状硬结、疼痛;9例皮肤灼伤。术后住院时间4～8 d,平均5.6 d。158例随访1～18个月,平均11.6月,未见复发。结论 腔内激光治疗大隐静脉曲张效果确切,创伤小。     

Association of the Platelet Glycoprotein Ⅰa C807T Gene Polymorphism With Risk of Myocardial Infarction in Chinese

Objectives To investigate the relationship of the GPIa C807T dimorphism to the risk of myocardial infarction (MI) in Chinese. Methods We did a case-control study including 100 patients and 110 controls with same race. An allele-specific polymerase chain reaction (PCR) was used for genotyping of C807T polymorphism. Results An apparent association was found between the T807 allele and MI among individuals younger than the mean age of 60 years (odds ratio,2.49; 95% confidence interval, 1.08 ～ 6.22 ). The T807 allele remained an independent risk factor for MI when age, sex, smoking, hypertension, diabetes, bodymass index, LDL-cholesterol and HDL-cholesterol were adjusted by logistic regression. Conclusions GPⅠa T807 appears to be an independent risk factor for MI.     

Teriparatide vs. calcitonin in the treatment of Asian postmenopausal women with established osteoporosis

This study compared the clinical efficacy, safety, and tolerability of daily subcutaneous injections of teriparatide and salmon calcitonin in the treatment of postmenopausal women with established osteoporosis in Taiwan. This 6-month, multicenter, randomized, controlled study enrolled 63 women with established osteoporosis. They were randomized to receive either teriparatide 20 μg or calcitonin 100 IU daily in an open-label fashion. Lumber spine, femoral neck, total hip bone mineral density (BMD), and biochemical markers of bone turnover were measured, and adverse events and tolerability were recorded. The results at 6 months showed that patients using teriparatide had larger mean increases in spinal BMD than those who used calcitonin (4.5% vs. 0.1%), but the BMD changes in these two groups at the femoral neck and the total hip were not significant. There were also larger mean increases in bone markers in the teriparatide group than in the calcitonin group (bone specific alkaline phosphatase 142% vs. 37%; osteocalcin 154% vs. 23%). We conclude that teriparatide has more positive effects on bone formation than salmon calcitonin, as shown by the larger increments of lumbar spine BMD and bone formation markers, and caused only mild adverse events and no significant change in liver, kidney or hematological parameters. Compared with the published global results, teriparatide seems to be equally effective and safe to use in this Asian population.     

慢性肝炎辨治五法

慢性肝炎（简称慢肝）属中医学“胁痛”、“黄疽”、“瘾积”等范畴。其病程长，疗效慢，且易反复发作。目前尚无特殊疗法。笔者通过研习有关文献，回顾长期临床验案，对慢性肝炎之证治略有心得，兹介绍如下。     

慢性鼻窦炎鼻息肉合并支气管哮喘患者鼻窦内镜术后对支气管哮喘疗效的影响

目的观察鼻窦内镜术(endoscopic sinu ssurgery，ESS)对慢性鼻窦炎伴支气管哮喘患者哮喘发作的影响。方法对210例慢性鼻窦炎患者施行ESS术，其中伴有支气管哮喘病史者42例(20．0％)。210例患者均于术前、术后采用酶联免疫吸附测定法(ELISA)检测外周血单个核细胞(PBMC)培养上清液中的白细胞介素4(IL-4)，干扰素γ(IFN-γ)，可溶性白细胞介素2受体(sIL-2R)和可溶性IgE低亲和力受体(solube CD23，sCD23)的含量，并与20例正常对照组进行比较。通过主观和客观标准评定42例患者哮喘发作及对皮质类固醇的耐受状况，并对术后患者进行为期1年(10例)和3年(32例)的随访。结果鼻窦炎合并支气管哮喘患者术前PBMC培养上清液中IL-4，sIL-2R、sCD23含量较对照组显著升高，而IFN-γ含量较对照组显著减少。术后IL-4、sIL-2R、sCD23含量较对照组显著降低，而IFN-γ含量显著增高。术后哮喘改善水平由随访术后1年的45％提高到术后3年的70％。42例中32例(76％)哮喘发作次数明显减少，术前长期服用类固醇的2l例中，14例(67％)减少了对口服类固醇的使用。结论ESS对慢性鼻窦炎伴支气管哮喘患者的治疗有较满意的远期疗效。ESS能调节IL-4、IFN-γ sIL-2R、sCD23水平，降低哮喘的发作频率和对类固醇的依赖。     

Does the Suggested Lightwand Bent Length Fit Every Patient?: The Relation between Bent Length and Patient's Thyroid Prominence-to-Mandibular Angle Distance

Background: To date, no study has explored the effect of bent length on lightwand intubation. For successful intubation in daily practice, the authors found that bent length should be approximated to the patient's thyroid prominence-to-mandibular angle distance (TMD), but some patients have a TMD much shorter than the suggested bent length range. The purposes of this study were to understand TMD distribution in adults and to test the influence of bent length on lightwand intubation.

Methods: The TMD, airway, and demographic data of 379 patients were collected. To test the bent length influence, patients were enrolled in group A (158 patients, TMD <= 5.5 cm) and group B (131 patients, TMD > 5.5 cm) and were intubated randomly using the lower (6.5 cm) and upper (8.5 cm) limits of the suggested range. Success rate and lightwand search time were compared.

Results: In group A, the success rate was 98.8% with 6.5-cm bent length and 78.2% with 8.5-cm bent length (P < 0.05). Search times were 5.7 +/- 2.90 and 8.9 +/- 5.80 s with 6.5- and 8.5-cm bent length, respectively (P < 0.01). In group B, there was no statistical difference in success rate and search time between 6.5- and 8.5-cm bent length.     

铁打的营盘VS流水的人才空军总医院的"激将法"

“铁打的营盘流水的兵”,到哪儿都是这个理。可当“铁打的营盘”遭遇“流水的人才”结果会怎样?曾几何时,一度人才防线牢不可破的公立医院,在面临外资和民营医疗机构强大的“挖角”攻势下,不得不仓促应战。虽然目前公立医院在这场人才拔河较量中仍具优势,只是不知这种优势还能维持多久?