Changes in cardiovascular function induced by verapamil in healthy subjects and in patients with ischemic heart disease

Alterations in cardiovascular function induced by the acute intravenous administration of verapamil (5 or 10 mg) in 52 patients (29 with ischemic heart disease and 23 without heart disease) were evaluated with use of invasive techniques (right and left heart catheterization, left ventricular cineangiography, and coronary arteriography). The most significant changes were represented by a decrease in systemic vascular resistance and systemic arterial pressure, and an increase in heart rate and cardiac output. Contractility indexes were not depressed in either group, and altered ventricular wall motion tended to improve to a slightly smaller degree than in patients treated with nitroglycerin. The use of verapamil in patients with ischemic heart disease appears to be safe, and concern about the negative inotropic influences in humans no longer seems justified.     

二尖瓣置换术围手术期硝普钠的应用

本文介绍了20例二尖瓣置换术病人围手术期使用硝普钠的经验。术中和术后早期使用硝普钠可降低肾素-血管紧张素系统的活性、减轻外周血管阻力和后负荷,增强泵血功能,从而使心脏指数升高,降低术后高血压和肺水种的发生率。体外循环停止后,硝普钠与低浓度升压药并用可增强心肌收缩力,预防低排综合征     

Anaesthesia monitoring: the human factors component of technology transfer

Resistance to change in monitoring practices from within the anaesthesiology community is a formidable obstacle, and coercive and exhortatory solutions are likely to be unsuccessful in some situations. An analysis of publications about technology transfer and professional obsolescence, and application of this data to the practice of anaesthesia, reveals various stresses that technology transfer from research areas to the workplace may induce in vulnerable anaesthesiologists and account for their attitudes. It is suggested that the invaluable pronouncements of high profile anaesthesiologist groups must be supplemented by supportive behaviour by physicians and administrators at an institutional level. The human factors issues to be addressed include: (i) Monitored data acquisition skills. (ii) Possibility of acting on monitored data. (iii) Assistance for personal insight into attitudinal difficulties that may be encountered. (iv) Data supporting the value of the device. (v) Ergonomically effective integration of the monitor into the work station.Alternatively the perceptions of potential users may accurately reflect changes in their status in the new work situation created by monitors, and decision making aids that may or may not be derived from them. Thus, plans to present job satisfaction in related clinical areas or to associate the proposed new system with evaluation of its effect on patient outcome will be necessary. In this way the clinician becomes involved in clinical research, a quality of personal and quality care development.     

Effect of sperm preparation with TEST yolk buffer on sperm-binding capacity under hemizona assay conditions

Summary. The study was conducted to evaluate the diverse effect and clinical significance of TEST yolk buffer treatment on sperm samples of 128 infertile men. Sperm samples were incubated with TEST yolk buffer and control medium (Ham's F-10) at room temperature for 2 h. The hemizona indices (mean ± SE) of the TEST yolk buffer and medium-treated sperm samples were 29 ± 2.3% and 22 ± 1.6%, respectively. Inspection of the individual response of each sperm sample to TEST yolk buffer revealed that 63 samples (49%) improved (double the interassay variation = 28%) their binding to zona pellucida, 36 (28%) remained unchanged, whereas the binding capacity of 29 samples (23%) decreased. Furthermore, TEST yolk buffer treatment of 24 samples (19%) resulted in an increased binding beyond the hemizona index threshold set up at 23%. This level was previously shown to be the cut-off point between fertile and infertile sperm samples. It was concluded that when applied to an unselected group of infertile men, TEST yolk buffer significantly increased sperm binding capacity to the zona pellucida. However, only 19% of the sperm samples showed improvement with clinical significance. The other sperm samples may have improved, remained unchanged or even deteriorated independently on basic sperm variables. Thus, the effect of TEST yolk buffer treatment on sperm binding should be tested prior to its clinical use to avoid possible damage to certain sperm samples.     

The spermatozoal volume as indicative of the plasma membrane integrity (modification of the hypoosmotic swelling test). I. Methods

Summary. The aim of the present study was to establish a more differentiating indicator of plasma membrane integrity of spermatozoa than the classic version of the hypoosmotic swelling test according to Jeyendraan. Spermatozoa were prepared by density gradient centrifugation (90% Percoll) to select 'fertilization competent' spermatozoa only. After a second washing procedure sufficiently pure sperm cell suspensions were obtained. The volume distributions of these sperm cells were measured with a Coulter Counter at 25 °C after adaptation in 300 mosmolar NaCl solution resp. 150 mosmolar NaCl solution for 5 min. These volume distributions showed significantly different patterns for the isotonic and hypotonic stress situation in the simple salt solution. Moreover, the comparison of the response to hypoosmotic stress showed more than four reproducible characteristic patterns, promising well differentiated results for different sperm populations. The new method for the detection of hypoosmotic swelling effect might be a real and valuable functional parameter.     

Testicular amplificaion and impaired transmission of human butyrylcholinesterase cDNA in transgenic mice

Gene amplification occurs frequently in tumour tissues yet is,in general, non-inheritable. To study the molecular mechanismsconferring this restraint, we created transgenic mice carryinga human butyrylcholinesterase (BCHE) coding sequence, previouslyfound to be amplified in a father and son. Blot hybridizationof tail DNA samples revealed somatic transgene amplificationswith variable restriction patterns and intensities, suggestingthe occurrence of independent amplification events, in 31% (11/35)of mice from the FII generation but in only 3.5% (2/58) of theFII and FIV generations. In contrast, >10-fold amplificationsof the BCHE transgene and the endogenous acetylcholinesteraseand c-raf genes appeared in both testis and epididymis DNA from>80% of FIII mice. Drastic, selective reductions in testisBCHEmRNA but not in actin mRNA were detected by the PCR amplificationof testis cDNA from the transgenic mice, and apparently resultedin the limited transmission of amplified genes. The testicularamplification of the BCHE transgene may potentially representa general phenomenon with clinical implications in human infertility.     

Low-dose erythropoietin is effective and safe in children on continuous ambulatory peritoneal dialysis

Hypertension is one of the most important complications of erythropoietin (rHuEPO) therapy in dialysis patients. In this study, the effect of two different dosage regiments of subcutaneous rHuEPO on blood pressure [BP] was evaluated in 20 anemic children on continuous ambulatory peritoneal dialysis (CAPD). Patients were randomized to receive rHuEPO 50 U/kg, either once a week (group 1, 50 U/kg per week) or three times a week (group 2, 150 U/kg per week). At the beginning of the study, 8 patients in group 1 and 8 patients in group 2 were on antihypertensive therapy. In group 1, the hematocrit increased gradually and significantly from 18.98%±1.79% to 30.1%±1.62% after 6 months, while in group 2 it rapidly increased from 19.53%±1.86% to 32.4%±1.11% after 3 months. A significant increase in the mean arterial BP was observed in group 2. Antihypertensive therapy had to be increased in all of the 8 previously hypertensive patients and had to be initiated in 1 of the 2 originally normotensive patients in the same group. None of the patients in group 1 required a change in antihypertensive medication. We conclude that during treatment with rHuEPO pre-existing hypertension and the dose of rHuEPO are the most important risk factors for the development or worsening of hypertension in children on CAPD, and gradual elevation of hematocrit by low-dose rHuEPO avoids the development of severe hypertension. Received December 11, 1995; received in revised form September 16, 1996; accepted September 19, 1996     

喉癌患者染色体对致突变剂诱发畸变的敏感性研究

采用平阳霉素作为诱变剂，对２８例喉癌患者和２３例正常人做外周血淋巴细胞染色体对诱变剂敏感性研究，结果显示喉癌患者的染色体总畸变率、每细胞染色单体断裂率（ｂ／ｃ值）和细胞畸变率分别为１．９８％±０．０５％，０．５７％±０．３５％和４２．８％±１２％。正常人则分别为０．９４％±０．０４％，０．２８％±０．１２％和２７％±１２％。经统计学处理，喉癌患者组与正常人组的差异有高度显著性。并结合实验结果探讨了染色体对致突变剂的敏感性与患喉癌风险的关系。     

Correlation between sperm penetration into the human zona pellucida and in vitro fertilization rates

Summary.  Sperm penetration into the zona pellucida of unfertilized oocytes, and its correlation with in vitro fertilization rates of the sibling oocytes, were assessed. This was performed in order to evaluate the prediction rate of the sperm penetration test into the zona pellucida. Unfertilized oocytes ( n =1872) from 371 cycles were pipetted through a microcapillary, and the remaining sperm cells penetrating the zona pellucida were counted. The mean (±SD) number of spermatozoa that penetrated the zona pellucida of unfertilized oocytes was 12.9±16.37. A significant correlation was found between the fertilization rate and the mean number of spermatozoa that penetrated into the zona pellucida of the unfertilized sibling oocytes (r = 0.48; P < 0.001), or the percent of unpenetrated zonae pellucidae in a cohort (r= —0.43; P < 0.001). However, a distinct variation in the number of spermatozoa that penetrated into the zona pellucida was detected. A step-wise regression analysis proved the number of spermatozoa penetrating the zona pellucida to be more predictive for fertilization rates than the variable of percent of unpenetrated zonae pellucidae. The results imply that although there is interdependence between penetration into the zona pellucida and fertilization rate, the predictive value of sperm penetration test for prognosis and future management after the first in vitro fertilization attempt, is limited.     

Indirect detection of anti-acetylcholinesterase compounds in microcolumn liquid chromatography using packed bed reactor with immobilized human red blood cell acetylcholinesterase and choline oxidase

The inhibiting compounds were separated by micro-column liquid chromatography in the mobile phase containing the natural substrate acetylcholine. A home-made packed bed microbioreactor system containing immobilized enzyme acetylcholinesterase (ACHE) in human red blood cell membrane and choline oxidase (CHO) from alcaligenes was used for the post-column conversion of acetylcholine to hydrogen peroxide which was detected by an electrochemical detector. The inhibition effect of the solutes caused a decrease in the acetylcholinesterase activity, a decrease in the formation of hydrogen peroxide and also a decrease in the response corresponding to the concentration of the solutes. The rate of the enzyme regeneration was also recorded. The micro-system was compared with a conventional LC system comprising commercially prepared enzyme reactor. The stability of the enzymes is at least 3 weeks at ambient temperature. The limit of detection depends on biological activity of inhibition and for galanthamine was 1 pmol.