Migraine-like headaches associated with nickel allergy requiring removal of atrial septal defect closure device

There is a deficit of literature regarding the association between nickel allergy–induced symptoms and implanted devices. This report describes a case of nickel allergy causing debilitating migraine-like symptoms, failing to resolve with medical therapy, requiring surgical removal of the device and repair of the defect.     

Response of neurons in primary somatosensory cortex of cat following prolonged exposure to strong sinusoidal mechanical stimuli

Psychophysical studies in humans have demonstrated adaptation of the mechanoreceptive submodalities of flutter and vibration after prolonged presentation of a strong adapting, or conditioning, stimulus. In our studies we recorded from single neurons in cat primary somatosensory cortex, and followed a paradigm in which the response of a single unit was measured before and after the presentation of a strong conditioning stimulus. Our findings show no adaptive response in the 30 sec period immediately after cessation of the conditioning stimulus, and suggest that other parallel ascending pathways or somatosensory cortical areas other than SI account for these psychophysical observations.     

压力波对豚鼠耳蜗血管纹、毛细胞心钠素免疫活性改变的研究

目的为探讨压力波的致聋机理,对豚鼠耳蜗血管纹(SV)、毛细胞(HC)中心钠素免疫活性(ANP-IR)的改变及与听阈阈移的相关性进行研究。方法采用免疫细胞化学(ABC法)法、图像分析听性脑干反应测听技术(ABR)对压力波暴露后不同时间分组的豚鼠耳蜗SV、HC中ANP-IR产物进行检测。结果压力波暴露后6、12、24h和48h组SV组织中ANP-IR光密度值较对照组均有明显的差异(P<0．05),其中24h组最高;冲击波暴露后6、12、24h组内毛细胞(IHC)中ANP-IR阳性产物的光密度值较对照组明显增高(P<0．05),其中以12h组最高。二者的变化均与听阈阈移有明显的正相关性(r1=0．8175,P＞0．05;r2=0．9185,P＞0．05)。而外毛细胞(OHC)中ANP-IR阳性产物变化不明显。结论压力波暴露后,SV组织中ANP的增高可能是内耳的一种代偿机制;IHC和OHC中ANP-IR的变化可能是冲击波对其损伤机制的不同表现。     

常用控制心室率药物的随机对照研究

目的;比较五种常用药物组合对慢性房颤患者静息及活动状态下心室率的控制作用。方法：顺序住院和６０例慢性心房纤颤患者由不参与研究者随机分为五组相比即Ａ组疃 高辛０．２５ｍｇ／ｄ;Ｂ组：单用倍它乐克５０ｍｇ／ｄ;Ｃ组：单用异搏定（缓释制剂）２４０ｍｇ／ｄ;Ｄ组：０．２５ｍｇ地高辛与５０ｍｇ倍它乐克联用;Ｅ组：０．２５ｍｇ地高辛与２４０ｍｇ异搏定（缓释剂）联用。每组１２例。统计处理用ＡＮＯＶＡ、非参数统计     

射频消融治疗阵发性室上性心动过速262例分析

经导管射频消融治疗阵发性室上性心动过速（ＰＳＶＴ）２６２例,探讨ＲＦＣＡ治疗ＰＳＶＴ的安全性及疗效。方法：房室结双径路改良采用下位法;左侧旁道采用冠状窦电极粗标,大头电极在心室国标。右侧旁道采用左前斜４５度。大头电极在心房侧三尖瓣环处细标;房扑时标测心房激动顺序,用隐匿必拖法确定折返环部位,在心房内行线性消融方法治疗。结果：２６２例中慢－快型房室结折生心动过速（ＡＶＮＲＴ）７８例。,房室折返性心动     

Adenosine for the management of patients with tachycardias--a new protocol

We developed a new protocol for diagnosis and treatment of patientswith sustained tachycardias (heart rate > 150 beats. min^–1).The patients first underwent vagal manoeuvres; if those remainedunsuccessful, i.v. adenosine in increasing doses of 6, 12, and18 mg was administered until sinus rhythm (SR) or transientatrioventricular (AV) block, unmasking the underlying rhythm,was recorded. In the latter and in the non-responding casesother antiarrhythmics were applied. Ninety-three episodes of tachycardia in 46 patients were treatedaccording to this protocol. Six episodes (6%) were terminatedby carotid massage, 64 of the remaining 87 episodes (74%) respondedto adenosine with return to SR. Conversion to SR occurred moreoften in episodes with narrow- than in wide-complex tachycardia(81 vs 59%, P<005). To achieve SR, the mean adenosine dosewas lower in narrow- than in wide-complex tachycardia (13±8vs 21 ± 10 mg; P<0.01). The duration of asystole afteradenosine did not differ between these two groups, whereas theduration of arrhythmia after adenosine differed significantly(8.5 ± 5.8 vs 18.6 ± 22.9 s; P<0.05). Sideeffects of adenosine such as flush, dyspnoea, and chest paindid not seem to be dose dependent and occurred in about 20%. According to our protocol, in more than 75% SR was achievedin patients with sustained tachycardias after vagal manoeuvresand adenosine.     

Some observations on the mechanism of pressure related atrial fibrillation

In order to investigate the effect of atrial pressure on thepropensity of the atria to fibrillate and the mechanism of thisassociation, the right atrial pressure was changed acutely bytransfusion-bleeding in 12 anaesthetized open-chest dogs. Undervarious atrial pressures the conduction time was measured betweentwo pairs of hook electrodes positioned on the two atrial appendagesrespectively. The effective refractory period was measured bycontinuous pacing of the right atrium at a 250 ms cycle lengthat double threshold intensity and interpolating a progressivelyearlier stimulus after each eighth paced beat. The propensityof fibrillation was studied by rapid (450 min^–1) pacingof the atria at double threshold intensity for 10 s at differentatrial pressures. At a high (14 mmHg) atrial pressure the conductiontime (45.7 ± 14.2 ms) was significantly (P<0.01) longer,the effective refractory period (157.9 ± 15.2 ms) significantly(P<0.01) longer and the atrial fibrillation (11/19 or 57.9%)significantly (X² = 9.95, P<0.001) more common than at alow ( 10 mmHg) pressure (35.2 ± 11.6, 146.2 ±12.4, 3/24 or 12.5%, respectively). Analysis of variance showedthat the probability of atrial fibrillation was significantlyaffected by the atrial pressure but not by either the conductiontime or the effective refractory period The findings suggestthat an increase in right atrial pressure by acute volume overloadprolongs the inter-atrial conduction time and right atrial refractorinessand increases the propensity of the atria tofibrillate by rapidatrial stimulation. The effect of atrial pressure on fibrillationdoes not seem to be mediated by the prolonged atrial refractorinessor conduction time.     

Pharmacokinetic-pharmacodynamic (PK-PD) modeling for a new antihypertensive agent (neutral metalloendopeptidase inhibitor SCH 42354) in patients with mild to moderate hypertension

SCH 42354, a neutral metalloendopeptidase (NEP) inhibitor, is the pharmacologically active form of the prodrug SCH 42495. It exerts antihypertensive effects by potentiating atrial natriuretic peptide (ANP) activity through inhibition of its hydrolysis by NEP. The objective of this study was to characterize the pharmacokinetics (PK) and pharmacodynamics (PD) of SCH 42354 in hypertensive males. SCH 42495 12.5 to 400 mg was administered orally to hypertensive men twice daily in a double-blind, placebo controlled multiple-dose parallel group design. Plasma SCH 42354 concentration and diastolic blood pressure (DBP) data were used to develop a PK-PD model using two approaches. In the first (non-integrated) approach, the link model was used to predict effect-site concentrations, and was applied to data obtained at the 300 and 400 mg BID doses only; data at the other (lower) doses were not amenable to modeling because of high variability. Effect-site concentration and DBP data were then fit to a sigmoid E_max PD model. For the 300 mg BID dose, PD parameters were: maximum effect (E_max), 8.1mmHg; no-drug effect (Eo), 3.6 mmHg; concentration corresponding to 50% of maximum response (EC₅₀), 0.87 g·ml^–1; and gamma, 3.9. In the second (time-integrated) approach, plasma SCH 42354 concentration and effect data obtained over the entire dose range were integrated with respect to time. Average plasma concentration and DBP data were then fit to a simple E_max PD model. PD parameters obtained over the dose range were: E_max, 10.3 mmHg; Eo, 2.0 mmHg; and EC₅₀, 0.7 g·ml^–1. These were similar to the estimates obtained from the first approach, demonstrating that the integrated (average) data allow PK-PD modeling over the (entire) dose range. The analysis showed that, at steady-state, a 400 mg BID dose of SCH 42495 produced an approximate 10 mmHg decrease in DBP in hypertensive males; the average plasma SCH 42354 concentration attained at this dose was approximately 1.8 g·ml^–1.     

激光心肌血管重建术围手术期及术后早期心血管活性肽的变化

Objective: To investigate the changes of cardiovascular active peptides duringperioperation and early stage after transmyocardial laser-revascularization (TMLR). Methods: Tooperate on the chest, make 13 -- 27 channels with COZ laser (home-made machine ) on the anterior,lateral and latter parts of left ventricular wall of the heart in six patients with coronary heart diseasewho could not be treated by PTCA and CABG. The contents of atrial natriuretic peptide (ANP) .brainnatriuretic peptide(BNP)' adrenomedullin (Adm) and endothelin (ET) in pericardial fluid and bloodplasma were determined by immunoradioassay. Results: COmpared with healthy controls, the plasmalevels of ANP. BNP. Adm and ET in patients before TMLR were 11. 0 \ 22. 9. 3. 1 and 1. 3 timeshigher(p < 0. 01 ), respectively. After TMLR the contents of these four peptides in patient plasmareduced gradually. Four weeks after operation, they were 61. 0 % .58. 6 % .63. 4 % and 55. 3 % lower, respectively, than those before TMLR (P < 0. 01 ). Conclusion: TMLR apparently improved thecardiovascular endocrine function of patients with severe heart failure.