美托洛尔治疗右室流出道室性早搏的效果观察

目的：观察美托洛尔对起源于右室流出道室性早搏的疗效。方法：选择起源于右室流出道的室性早搏患25例，给予美托洛尔治疗，剂量从6．25mg开始，无不良反应后，逐渐加量，最大剂量每天100－150mg，疗程3个月，用药前后查12导联体表心电图、24小时动态心电图及结合临床症状进行评定。结果：①临床症状评定：胸闷心悸25例，治疗后减轻20例，有效率为80％；焦虑20例，治疗后症状均消失，有效率为100％；头晕14例，治疗后减轻12例，有效率为85．7％。②室性早搏评定：25例中达到室性早搏抑制率70％有11例，有效率为44％；平均室性早搏抑制率为45．6％，6例成对室性早搏抑制率为80％，3例短阵室速消失，平均心率降低12．6／min。③生化指标：血糖、胆固醇、甘油、三酯治疗前后无明显改变。④2例因血压低未加药量。结论：美托洛尔治疗起源于右室流出道室性早搏疗效肯定，尤其对运动后早搏增多疗效较好，临床太改善较显，观察中未发现明显不良反应，无致心律失常现象。     

Body Surface Mapping and Nontraditional ECG Leads in Patients with Wolff-Parkinson-White Syndrome

A method of ECG mapping from 90 points on the chest surface is described in 41 male and 17 female patients, aged 6 to 59 years. All also underwent invasive electrophysiological investigation and intraoperative epicardial mapping. Fifty-two patients had one, three patients two, and one patient had three anomalous accessory pathways. Two patients had nodoventricular tracts (Mahaim fibers). We distinguished seven zones along the atrioventricular groove (AVG) to compare the data derived from epicardial, endocardial, and body surface mapping. A microcomputer was used for the analysis of all ECGs to construct and analyze the isopotential maps. The criterion for localization of the anomalous accessory pathways was determined after analysis of the data from all 58 patients. The localization criterion was the appearance of a minimal deflection (-0.09 +/- 0.03 mV) on the surface isopotential maps within the first 0.28 msec of the QRS complex. This criterion for localization of anomalous accessory pathways from the chest surface was proposed on the basis of comparison of data from selective coronary angiography, the ventriculogram, and the chest X ray i.e., radiographic-topographic-anatomical data. In 20 patients, 10-20 nontraditional ECG leads were recorded from the chest to reflect the atrioventricular groove. The number of nontraditional ECG leads depended on patient age, weight, and height. Localization of the accessory pathway in one of the seven zones was established by the earliest delta wave and its maximum deviation. It was possible to localize the anomalous accessory pathway and to suspect multiple pathways in 95% of cases using nontraditional ECG leads and the listed criteria.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pregnancy augments nitric oxide-dependent dilator response to acetylcholine in the human uterine artery

The influence of pregnancy on the dilator effects of acetylcholine in the isolated human uterine artery was investigated. Acetylcholine (0.1 nM to 0.1 microM) produced concentration- and endothelium-dependent relaxation of norepinephrine (3 microM)-induced contraction. The relaxation was greater in arteries from pregnant patients (P arteries) than from non-pregnant patients (NP arteries). The maximal relaxation was 53.5+/-3.4% (n=21) in P arteries and 23.5+/-2.5% (n=35) in NP arteries. In both P and NP arteries the cholinergic relaxation was increased in the presence of superoxide dismutase and greatly reduced in the presence of the nitric oxide synthase inhibitors, NG-mono-methyl L-arginine (L-NMMA) and L-nitro-arginine-methylester (L-NAME). The effect of these nitric oxide synthase inhibitors was reversed by L- arginine. We conclude that pregnancy enhances acetylcholine-induced nitric oxide synthesis and release in the human uterine artery.      

Increased number of substitutions in the D-loop of mitochondrial DNA in the sudden infant death syndrome

The purpose of the present study was to investigate substitutions in the D-loop of mitochondrial DNA (mtDNA) in sudden infant death syndrome (SIDS) and controls, since several observations indicate the involvement of mtDNA mutations in SIDS. These include elevated levels of vitreous humour hypoxanthine in SIDS victims, familial clustering without mendelian traits, and observations of increased sleepiness and a lower activity score in infants who later succumbed to SIDS. Eighty-two cases of SIDS and 133 controls were investigated and the D-loop sequences were recorded in the base-pair range 16 055-16 500 in the mtDNA sequence. The sequencing was carried out using the Applied Biosystems Sequenase dye terminator method and a ABD373A sequencer. The recorded D-loop sequences were compared with the Cambridge sequence and differences were recorded as substitutions. The SIDS cases had a tendency towards a higher substitution rate in the D-loop than the controls ( p = 0.088). This observation makes it interesting to search for deleterious mutations in other locations in the mtDNA.     

阿克拉霉素A聚氰基丙烯酸异丁酯毫微粒冻干针剂体内外抗肝癌活性

阿克拉霉素A聚氰基丙烯酸异丁酯毫微粒的冻干针剂,能明显抑制体外培养人肝癌细胞株7703的生长,IC50为0.28μg·ml^-1。在0.8μg·ml^-1浓度时,克隆形成抑制率为90%,抑制作用有明显剂量依赖关系而未见明显时间依赖关系。静脉给药后,对常位移植人肝癌模型裸小鼠的抑瘤率为86.84%,肿瘤细胞增殖活性阳性率为20.83%。体内外均显示明显的抗肝癌活性,且体内抗肝癌活性比阿克拉霉素A冻干针剂强。     

Structuring a safer donor-replacement program

BACKGROUND: Replacement donors are more likely than volunteer donors to have positive or abnormal tests for transfusion-transmissible disease. In an effort to increase the donor pool, workers sought to identify a safer replacement-donor subgroup that may be acceptable for routine donations. STUDY DESIGN AND METHODS: In a retrospective review and cohort study, the replacement-donor effect was separated from the new- donor effect. The relative effect the replacement donor has on the risk of transfusion-transmissible diseases, donor retention, and frequency of returning donations was then quantified by comparison against the effect of repeat volunteer donors. RESULTS: The replacement donor had 3.1 times the risk and 0.72 times the donor retention rate and made 0.81 times as many returning donations as the repeat volunteer donor. The figures for the new-donor effect were similar. The two risks were additive, making a new replacement donor particularly hazardous. If replacement donations only from repeat replacement donors were considered, the donor risk and the number of donations per returning donor were made comparable to those for the general (combined) volunteer donor. CONCLUSION: The negative effect of the replacement donor is similar in magnitude to that of the new volunteer donor. A replacement-donation program targeting repeat replacement donors has an acceptable risk profile and may be a valuable adjunct to the collection of blood from general volunteer donors.