工频磁场辐照导致细胞连接蛋白Cx43的异常移位

目的　研究 5 0Hz正弦磁场对细胞连接蛋白Cx4 3移位的影响 ,以探索极低频磁场 (ELFMF)抑制细胞间隙连接通讯 (GJIC)的机制。方法　用 5 0Hz、0 .8mT的正弦磁场和 (或 )十四酰基咐哌醇酯 (TPA ,5ng/ml)对培养的中国仓鼠肺成纤维细胞 (CHL)处理 2 4h(其中TPA处理 1h)。采用间接免疫荧光细胞化学法和激光共聚焦显微镜进行连接蛋白Cx4 3定位的测定 ;采用Westernblot方法检测胞浆和核内Cx4 3蛋白的含量。结果　正常组细胞间连接处有明亮的点状标记 ,连接成线 ;TPA处理组、0 .8mT正弦磁场单独作用组及 0 .8mT正弦磁场联合TPA处理组细胞的连接处标记斑点均较正常组减少 ,大量Cx4 3蛋白标记斑点出现在胞浆内 ,且在核附近聚集。各组核内Cx4 3蛋白条带很淡 ,而胞浆内Cx4 3蛋白含量ELF组 (2 .0 3± 0 .89)和TPA组 (2 .4 3± 0 .82 )明显增加 ,与正常组 (1.0 4± 0 .17)相比 ,差异有显著性 (P <0 .0 1)。结论　 5 0Hz正弦磁场直接和 (或 )协同TPA抑制体外培养细胞GJIC功能与细胞连接蛋白Cx4 3内移至胞浆有关     

Radiofrequency Ablation-Induced Asystole During Transaortic Approach for a Left Anterolateral Accessory Pathway

RF Ablation-Induced Cardiac Asystole. We present a case of cardiac asystole induced by radiofrequency catheter ablation of a left anterolateral accessory pathway in a 28-year-old woman with Wolff-Parkinson-White syndrome who was experiencing recurrent palpitation. Radiofrequency current applied on the ventricular aspect of the mitral annulus corresponding to the aforementioned site provoked profound slowing of the sinus rate preceded by disappearance of the preexcitation, and then asystole ensued. The proposed causal mechanism was a reflexogenically mediated hypotension-bradycardia syndrome (Bezold-Jarisch-like phenomenon) through stimulation of either nearby vagal afferent pathways or sensory terminal receptors at the ablation site.     

Focal Atrial Tachycardia:

Atrial Tachycardia. Introduction : Reports about the clinical and electrophysiologic characteristics of focal atrial tachycardia vary widely. Furthermore, the impact of age, gender, associated cardiac diseases, mechanism, location of atrial tachycardia, and the prediction of results of radiofrequency catheter ablation was not clear. The purpose of this study was to further understand the clinical and electrophysiologic characteristics of focal atrial tachycardia and the prediction of results of radiofrequency ablation.
Methods and Results: We searched the literature published between January 1969 and July 1997 using the key word "atrial tachycardia" from the MEDLINE and National Library of Medicine systems. The items analyzed were age, sex, cardiac disease, mechanism, attack pattern, cycle length, location, number of atrial tachycardias, results of ablation, and recurrence after ablation. Multivariate analysis showed that age and paroxysmal type of tachycardia were independent predictors of nonautomatic mechanism; age and presence of other cardiac diseases were independent predictors of multiple atrial tachycardias, and age also was the independent predictor of right-sided atrial tachycardia. Atrial tachycardia located in the right atrium was the only significant predictor of successful radiofrequency catheter ablation. Other cardiac diseases and multiple atrial tachycardias were the significant predictors of recurrence after initial successful radiofrequency catheter ablation.
Conclusion : Patient age is closely related to the clinical and electrophysiologic characteristics of atrial tachycardia based on our reanalysis, which found that patient age is an independent predictor of nonautomatic mechanism, right atrial location, existence of multiple atrial tachycardias, and recurrence of atrial tachycardia after initial successful ablation.     

Augmented Two-Channel Arrhythmia Detection: An Efficient Diagnostic Method for Implantable Devices

ICDs are highly effective in preventing sudden cardiac death. However, inappropriate device shocks caused by false-positive diagnoses are estimated to happen in 20% of all patients. The need for implantable electrical devices to detect with precision arrhythmias requiring therapy has spawned a variety of proposals for better means of tachycardia identification. To address this problem, the augmented two-channel arrhythmia detection (A2CAD) algorithm, a real-time scheme utilizing timing and morphology from both the atrial and ventricular channels, is introduced. The algorithm uses rate detection as a first stage and augments this with morphological signal analysis in rhythms that confound the rate only diagnoses. The software executes in real-time (online), and has been tested on 60 passages of two-channel intracardiac signals. The following arrhythmias constituted the test set: 10 AF and/or atrial flutter; 15 SVT; 16 VT; 10 ventricular flutter or VF; 5 sinus tachycardia; and 4 cases of AF concurrent with VF. Results from 60 patient cases indicate 57 (95%) of 60 success rate for A2CAD, validating its potential for implementation in future implantable devices.     

Hypercholesterolaemia in patients with hepatocellular carcinoma

Ninety-one (11.4%) subjects with hypercholesterolaemia (serum cholesterol level more than 250 mg/dL) of 792 Chinese patients with hepatocellular carcinoma (HCC) were studied in Taiwan. All 91 patients had large tumours greater than 7 cm in diameter and a tumour volume greater than 50%; 56 (61%) of these patients manifested tumour involvement in both lobes of the liver. The HCC patients with hypercholesterolaemia had significantly higher mean serum levels of albumin, triglyceride and alpha-fetoprotein (AFP) compared with age-sex-tumour volume matched HCC patients without hypercholesterolaemia. The associated incidence of hypoglycaemia in hypercholesterolaemic HCC patients was significantly higher than in HCC patients without hypercholesterolaemia (15/90 vs 4/90; P = 0.01). There was no significant difference in the survival analysis between HCC patients with and without hypercholesterolaemia. Eight and 11 of hypercholesterolaemic HCC patients had their tumours surgically resected and received transcatheter hepatic arterial chemoembolization (TAE), respectively. Serum cholesterol levels fell to the normal range after treatment and rose to abnormal levels again when tumours recurred after surgery or progressively enlarged after TAE. The change in pattern of serum cholesterol was parallel to the change in serum AFP. Serum cholesterol levels may serve as another marker in identifying tumour recurrence and the presence of a viable tumour mass in hypercholesterolaemic HCC patients who have received surgical resection or TAE.     

Haemodynamic effects of enalaprilat on portal hypertension in patients with HBsAg-positive cirrhosis

Abstract It has been suggested that enalaprilat inhibits the renin-angiotensin-aldosterone system in plasma and tissue; it may therefore reduce portal vascular pressure owing to secondary hyperaldosteronism in patients with liver cirrhosis. In order to evaluate this concept, 20 patients with hepatitis B surface antigen (HBsAg)-positive liver cirrhosis and portal hypertension received an intravenous infusion of 2.5 mg of enalaprilat. Wedged hepatic venous pressure, free hepatic venous pressure and cardiac index were measured before, immediately after, and then 15 min, 30 min and 1 h after intravenous enalaprilat infusion. The mean pressure gradient between wedged hepatic venous pressure and free hepatic venous pressure was significantly decreased, by 13% immediately after, 18% at 15 min, 23% at 30 min and 13% at 1 h after infusion of enalaprilat. Thirteen patients experienced a decrease of hepatic venous pressure gradient (HVPG) greater than 5 mmHg, another three 3-5 mmHg and the remaining four patients exhibited no significant change in HVPG. Systemic haemodynamic indices, including pulmonary arterial pressure, pulmonary capillary wedge pressure and central venous pressure, decreased significantly at 15 and 30 min after enalaprilat infusion ( P < 0.01). Liver function, renal function and blood routine before and after enalaprilat infusion showed no significant changes. There were no adverse effects during or after enalaprilat infusion. We conclude that enalaprilat infusion can quickly and safely reduce the hepatic venous pressure gradient in patients with HBsAg-positive cirrhosis.     

Phototoxicity of Herbal Plants and Herbal Products

Plants are used by humans in daily life in many different ways, including as food, herbal medicines, and cosmetics. Unfortunately, many natural plants and their chemical constituents are photocytotoxic and photogenotoxic, and these phototoxic phytochemicals are widely present in many different plant families. To date, information concerning the phototoxicity and photogenotoxicity of many plants and their chemical constituents is limited. In this review, we discuss phototoxic plants and their major phototoxic constituents; routes of human exposure; phototoxicity of these plants and their constituents; general mechanisms of phototoxicity of plants and phototoxic components; and several representative phototoxic plants and their photoactive chemical constituents.     

The experience of cancer-related fatigue in Taiwanese children

The purpose of this study was to describe the experience of cancer-related fatigue in children of different ages in Taiwan. A total of 17 children with different stages of cancer were interviewed. The methods of data collection included interviews, participants' observations, medical chart reviews and the researcher's reflexive journals. Data were progressively analysed by using qualitative data analysis method throughout the process of data collection. The results indicated that children in all age groups used the word 'tiredness' or 'weary' instead of 'fatigue'. Patients in different age groups described the fatigue differently. Younger children (<9 years) reported that fatigue affected their ability to participate in physical activities. Children aged 10–12 years described fatigue as extreme tiredness that affected their daily lives both physically and psychosocially by altering their daily routine and school attendance and performance. Adolescents described fatigue as unrelievable tiredness that differed from normal tiredness and had a great impact on physical and psychosocial aspect, particularly altering their future life plans and self-performance. This study shows that the definition and impact of fatigue differs among children by age group. Defining and understanding the effects of fatigue can help clinicians assess fatigue and implement effective strategies to alleviate it.     

Characterization of Murine Liver-Derived Inhibitory Protein

Murine liver-derived inhibitory protein (LIP) capable of inhibiting human lymphocyte proliferation was highly purified from liver extract. Its molecular weight determined by gel filtration and SDS-PAGE was 105,000 and 38,400 respectively. LIP moved electrophoretically at the gamma-globulin region. Its activity in inhibiting lymphocyte proliferation was temperature-stable up to 60 degrees C, and pH-stable between 4 and 11. It was not cytotoxic to lymphocytes as shown in 51Cr-release experiments. The purified LIP possessed arginase activity.