Electrophysiological properties of the propafenone-analogue GE 68 (1-[3-(phenylethyl)-2-benzofuryl]-2-(propylamino)-ethanol) in isolated preparations and ventricular myocytes of guinea-pig hearts

GE 68 ((Rac.)-1-[3-(Phenylethyl)-2-benzofuryl]-2-(propylamino)-ethanol hydrochloride) is structurally related to propafenone, and exerts negative inotropic and negative chronotropic effects similar to the parent drug, but lacks any β-adrenoceptor blocking activity contrary to propafenone. Thus, the electrophysiological effects of GE 68 were studied in papillary muscles, left atria, Purkinje fibres, sinoatrial nodes and ventricular myocytes of the guinea-pig heart with the intracellular microelectrode technique and the patch-clamp technique in the cell-attached mode. The decrease of the maximum upstroke velocity (V˙_max) by GE 68 (1 to 10 μM) was use- and frequency-dependent. V˙_max recovered from the use-dependent block with a time constant of 4.1 ± 0.6 s. In papillary muscles and Purkinje fibres action potential duration was shortened, while it was prolonged in left atria and sinoatrial nodes. Half-maximal steady-state inactivation of the sodium channels was shifted to more negative membrane potentials (control: –91.5 ± 0.8 mV, 10 μM GE 68: –97.9 ± 2.5 mV). The peak of the current-voltage relationship and the reversal potential were not changed by GE 68. The amplitude of the unitary current remained unaltered, while open state probability was decreased. The most striking effect of GE 68 was an increase of the number of sweeps without single channel openings (1 μM: 2 fold, 10 μM: 6 fold). GE 68 also caused a decrease of the mean open times, and an increase of the mean closed times in unmodified and pronase-modified sodium channels. Besides the lack of β-adrenoceptor blocking activity, data present a faster recovery from the use-dependent block by GE 68 and a lower affinity to inactivated sodium channels compared to the reference drug propafenone, as well as differences in the effect on single channel kinetics. Received: 25 July 1996 / Accepted: 14 October 1996     

维持性血透患者的心理状态研究

研究我国血透患者的心理状况并进行针对性的心理治疗。方法 采用症状自评量表(SCL90-R)、多维度健康状况心理控制源量表(MHLC)、艾森克个性问卷(EPQ)及终末期肾脏病(ESRD)患者专用的生活质量表对北京六个医院透析中心的92名维持性血透患者进行了心理状态的研究,并与美国及加拿大相同的研究进行了比较分析。结果 本组的血透存在着抑郁、焦虑、恐怖等心理障碍,出现心理障碍的比例显著高于美国同类患者(P<0.01),且焦虑的发生率高于美国同类患者(P<0.01)。这些障碍与MHLC中机遇项分(CED)显著相关(P<0.01)。EPQ中神经质项分高者倾向于发生抑郁、焦虑等心理障碍。本组的血透患者客观生活质量较加拿大同类患者低(P<0.01),但在总的生活满意度上没有显著性差异。生活质量与心理及躯体因素均呈显著相关,心理障碍与躯体症状也显著相关(P<0.01)。结论 本组的血透患者心理状态与美国加拿大同类患者相比既有相同之处,又有特殊之处。我们应该兼顾病人的躯体和精神两方面的健康,努力提高他们的生活质量。     

Mature-age entrants to medical school: a controlled study of sociodemographic characteristics, career choice and job satisfaction

A comparison of 121 mature-age and 270 normal-age entrants who graduated from the University of Queensland Medical School between 1972 and 1987 shows that mature-age entrants are some 7 years older, are more likely to come from public (state) schools and less likely to have parents in professional/technical occupations. Otherwise, the two groups were similar in terms of gender, marital status, number of children, ethnic background and current practice location. The educational background of mature-age entrants prior to admission includes 44.6% with degrees in health-science areas and 31.4% with degrees in non-health areas. Reasons for delayed entry of mature-age entrants include late consideration of medicine as a career (34.7%), financial problems (31.4%), dissatisfaction with previous career (30.6%), poor academic results (19.8%), or a combination of the above factors. Motivations to study medicine include family influences (more so in normal-age entrants), altruistic reasons (more so in mature-age entrants) and a variety of personal/social factors such as intellectual satisfaction, prestige and financial security (similar for both groups) and parental expectations (more so in normal-age entrants). Mature-age entrants experienced greater stress throughout the medical course, especially with regard to financial difficulties, loneliness/isolation from the students and family problems (a greater proportion were married with children). While whole-course grades were similar in both groups, normal-age entrants tended to win more undergraduate honours/prizes and postgraduate diplomas/degrees, including specialist qualifications. Practice settings were similar in terms of group private practice, hospital/clinic practice or medical administration, but there was a greater proportion of mature-age entrants in solo private practice, and a smaller proportion in teaching/research. If given the time over, some two-thirds of both groups would choose medicine as a career. Reasons for job satisfaction include helping patients, intellectual stimulation and financial rewards. Reasons for dissatisfaction include pressure of work, red-tape/paperwork, 'doctor-bashing', long working hours, emotional strain, financial pressure, unfulfilled career expectations and irritation with trivial medical complaints.     

Deficiencies of Vitamins in CAPD Patients: The Effect of Supplementation

Concentrations of the vitamins B₁, B₂, B₆, B₁₂, C, folic acid,A, E and ß-carotene were determined in blood and 24-hdialysate in 44 CAPD patients. Twenty-five of these patientswere studied during chronic treatment (mean 313 days, range60–1034 days). Nineteen patients were studied during training.In a longitudinal study, 11 patients were analysed again after77–507 (mean 238) days. In both patient groups a considerable portion of patients (11%–64%)had blood concentrations indicative of a deficiency of the vitaminsB₁, B₆, C and folic acid. The average concentrations of thesevitamins were normal in both groups. The only abnormal findingwas the mean EGOT activity being deficient in patients on chronictreatment. Mean concentrations of vitamin A were above normalin both groups. In the longitudinal study a significant increaseof vitamin B₂ and a decrease of vitamin B₆ in blood was found. When compared to 24-h excretion in normal urine, loss with 24-hdialysate was low for vitamin B₁, normal to relatively highfor vitamin B₂ and B₆, but extremely high for vitamin C andfolic acid. The vitamins B₁₂, A, E and carotenoids were hardlydetectable in the dialysate. In ten other patients the effect of daily supplementation with2 mg vitamin B₆, 100mg vitamin C and 400 µg folic acidwas analysed during a 16-week period. In all patients a significantincrease in blood concentrations was obtained. It is concludedthat these dosages were sufficient to maintain a normal statusof these vitamins in CAPD patients.     

五所医院特需医疗服务状况调查

通过对上海医科大学附属华山医院、协和医院、北京同仁医院、中山医科大学附属第一医院、浙江医科大学附属第二医院开展的特需医疗服务情况的调查，论述了五所医院的具体做法，在对调查结果进行分析的基础上，就特需医疗服务的管理提出了建议。     

舟山海岛学生的碘营养状况对照研究

目的 :　海岛学生饮食结构中含有碘丰富的海产品。本研究旨在了解海岛学生的碘营养状况 ,评价食盐补碘的利弊。方法 :　对定海农村 (食用碘盐 )和岱山农村 (不食用碘盐 )的学校中随机抽取的 1 2个班级 ,对碘盐组和非碘盐组的饮食碘摄入和尿碘水平等变量进行描述 ,并分别以尿碘和甲状腺肿率为应变量进行单因素和多因素回归分析。结果 :　碘盐组除碘盐外每日碘摄入量中位数为 1 84μg,而不食用加碘盐的组为 1 0 5 μg,两组饮食碘摄入有显著性差异 (u=4.71 0 ,P=0 .0 0 0 ) ,而尿碘水平在食用碘盐组和不食用碘盐组分别为 1 6 9μg/L和 1 2 9μg/L,两组间有显著性差异 (u=6 .3 0 2 ,P=0 .0 0 0 )。多因素分析中性别和是否食用碘盐对尿碘水平有显著性意义 (P<0 .0 5 ,OR值分别为 0 .76 5 ,1 .93 3 )。甲状腺肿学生和正常学生的饮食碘和尿碘无统计学差异 (P>0 .0 5 )。Poisson回归分析中性别和是否食用碘盐对甲状腺肿率有影响 (P<0 .0 5 ,OR值分别为2 .2 5 ,3 .5 2 )。结论 :　舟山海岛学生要注意补碘过程中可能出现的碘过量问题。     

直流伺服系统中单神经元PSD应用的改进

常规PID控制具有结构简单、稳定性好、可靠性高等优点，在调速系统中被广泛应用。但常规PID控制的设计需依靠数学模型，负载、模型参数的变化及非线性因素等影响常规PID的精确调节。单神经元PSD控制器利用神经元的自学习、自组织能力，根据被控对象的变化情况对控制器的权值进行在线调整，达到在线调整PID参数的目的，并且采用无需对象模型的控制算法构成了自适应控制。与常规的PID调节器相比，具有更好的鲁棒性。同时，通过对PSD控制器的改进，在直流伺服系统的仿真应用中得到了较理想的结果。     

Dietary behaviour of an adolescent French male population

The dietary history method was used to determine the total energy and macronutrient intake, the distribution of daily energy from the different meals and the energy contribution of various food groups, in a population of 299 boys, aged between 10 and 15 years. The effects of age, the social status of the father (SPS), the ponderal index, the importance of breakfast or lunch, and the level of energy intake on dietary indicators, were studied. In our population, energy intake increased with increasing age but the energy contribution of macronutrients did not vary. The diet of boys whose fathers were in the upper SPS classes differed from the diet of those boys whose fathers were manual workers: for example they consumed less energy and pastries, but more animal protein (in percentage of energy intake), more dairy products, and more fruit. The ponderal index was negatively related to energy intake but positively related to protein intake, especially from meat and meat products. The energy intake from protein, animal protein and the energy contribution of dairy products, meat and meat products, fish and vegetables was lower among large eaters than among small eaters. The energy contribution of pastries, sugar and sweets was higher among large eaters.
Similarily, the energy intake from morning and evening snacks was also higher among large eaters. It should be noted that boys who had a substantial breakfast took in less energy from all other meals (including snacks and main meals). Such informaton is necessary in order to develop an effective health programme.     

Daily nutrient intake represents a modifiable determinant of nutritional status in chronic haemodialysis patients.

BACKGROUND: In maintenance haemodialysis patients, daily food intake is changeable; however, its relationship with nutritional status is unexplored. This study aimed to evaluate the isolated, long-term effect of daily nutrient intake on nutritional status in haemodialysis patients. METHODS: We performed a prospective 1-year controlled study in 27 chronic haemodialysis patients, without recognized risk factors for malnutrition. Each day for 1 week, four times in the year, we measured protein nitrogen appearance, and assessed dietary protein (DPI) and energy (DEI) intake from dietary diaries. We compared the nutritional outcome of patients spontaneously reducing nutrient intake below the threshold of 0.8 g/kg body weight/day for DPI and 25 kcal/kg body weight/day for DEI during the week (LOW, n = 8), with controls at adequate nutrient intake (CON, n = 19). An interventional 6-month study was then carried out in LOW to verify the cause-effect relationship. RESULTS: All patients showed a day-by-day reduction of whole nutrient intake during interdialytic period, which was mostly relevant in the third interdialytic day (L3). During the 1-year study, even in the presence of adequate dialysis dose and normal inflammatory indexes, body weight (68.0 +/- 5.5 to 65.8 +/- 5.9 kg), serum albumin (3.96 +/- 0.07 to 3.66 +/- 0.06 g/dl) and creatinine (9.2 +/- 1.1 to 8.1 +/- 0.7 mg/dl) significantly decreased in LOW but not in CON. Diaries evidenced in LOW a reduced number of meals at L3 that was explained by the fear of excessive interdialytic weight gain. During the interventional study, daily DPI and DEI increased at L3; this was associated with a significant increment of body weight, and serum albumin and creatinine levels. CONCLUSIONS: In maintenance haemodialysis patients the persistent, marked reduction of daily nutrient intake, even if limited to a single day of the week, is an independent determinant of reversible impairment of nutritional status.     

硫喷妥钠治疗小儿难治性惊厥持续状态疗效观察

目的 探讨对小儿难治性惊厥持续状态的有效治疗方法。方法 对14例小儿难治性惊厥持续状态采用硫喷妥钠治疗并观察疗效。结果 硫喷妥钠治疗有效率为100％，1例出现呼吸抑制，3例于停药后复发。结论 硫喷妥钠对小儿难治性惊厥持续状态有明显疗效，但易发生呼吸抑制。惊止后应维持一段时间，以免复发。