Characterization of the effects of histamine on the transmembrane electrical activity of guinea-pig and rabbit SA- and AV-node cells

Summary The effects of histamine on the transmembrane electrical activity of cells of small preparations (0.5 × 0.5 mm) of guinea-pig and rabbit sinoatrial- and atrioventricular-nodes were studied. Histamine at concentrations above 10^–7 mol/l increased the firing rate, the rate of diastolic depolarization, the maximum diastolic potential, the amplitude and the maximum rate of depolarization of the action potential of pacemaker cells of rabbit and guineapig sinoatrial cells and rabbit atrioventricular cells. These effects were antagonized by the HZ-receptor blocker cimetidine (2.5 × 10^–6 mol/1) but they were not modified by the H₁-receptor blocker chlorphenamine (2.5 and 5×10^–6 mol/1). Small preparations of guinea-pig atrioventricular node did not exhibit spontaneous activity, but it was induced by histamine and blocked by cimetidine. Histamine increased the maximum upstroke velocity of propagated action potential of cells of the central part of complete atrioventricular node in both species studied. These effects were blocked by cimetidine, but not by chlorphenamine. It is concluded that the increase in automaticity induced by histamine in guinea-pig and rabbit sinoatrial and atrioventricular nodes was due to stimulation of H₂receptors. Histamine did not depress electrical activity of atrioventricular node cells, but rather increased it. This effect was due to H₂-receptor stimulation. Send offprint requests to: J. Sanchez-Chapula at the above address     

下肢深静脉瓣功能不全的二维及彩色多普勒超声诊断

目的 探讨下肢深静脉瓣功能不全的二维及彩色多普勒超声声像图改变。方法 应用二维及彩色多普勒超声检查下肢深静脉瓣功能不全36例，47条腿，观察下肢静脉血管及瓣膜的解剖结构和血流动力学改变。结果 有静脉瓣功能不全的患肢静脉管腔内径均有不同程度增宽，瓣膜均有不同程度的改变，脉冲多普勒显示返流频谱返流时间大于0.5s。结论 该检查对诊断下肢深静脉瓣功能不全有较高的实用价值。     

Ultrasonography in the detection of cervical incompetency

In 80 pregnancies with clinical and ultrasonic signs of cervical incompetency, the length of the cervix and the thickness of the anterior wall of a lower uterine segment have been evaluated ultrasonically. We have also measured the width of the endocervical canal and studied the prolapse of fetal membranes (with fetal parts) into the endocervical canal. We evaluated these same parameters in 80 healthy pregnancies. The length of the cervix, the thickness of the anterior wall of a lower uterine segment, and the width of the endocervical canal were followed longitudinally in the patients from the 10th to the 36th gestation week. No statistically significant differences between age groups were found. In four age groups at risk for cervical incompetency, cervical lengths and wall thickness were significantly different (p less than 0.001) from those in comparable controls. Forty-five percent of the patients in the at-risk group, with cervical cerclage, delivered at 37.3 (range: 32 to 41) weeks and 6.25% of pregnancies ended in abortion when the amniotic membrane herniated into the cervical canal, with or without some part of the fetus.     

β 1- andβ 2-adrenoceptor binding and functional response in right and left atria of rat heart

Summary The properties of ₁- and ₂-adrenoceptors in right and left atria of rat heart, and their roles in mediating chronotropic and inotropic responses to-adrenoceptor agonists were examined. [¹²⁵I](-)-pindolol (¹²⁵IPIN) bound saturably and specifically to a single class of high affinity sites in homogenates of both right and left atria. Thek ₁'s for association in right and left atria were 6.5×10⁹ l/mol-min and 2.3×10⁹ l/mol-min respectively, while thek _–1's for dissociation were 0.20 min^–1 and 0.17 min^–1. The kinetically determinedK _D's were 75 pmol/l in right and 30 pmol/l in left atria and were similar to the equilibriumK _D's determined from Scatchard analysis of saturation isotherms of specific¹²⁵IPIN binding. Inhibition of¹²⁵IPIN binding by-adrenoceptor antagonists was stereoselective and the order of potency was timolol > 1-propranolol > d-propranolol > sotalol. Inhibition by ₁- and ₂-adrenoceptor subtype selective antagonists yielded flat displacement curves with low Hill coefficients. Nonlinear regression analysis of displacement by ₁-selective (practolol, atenolol and metoprolol) and ₂-selective (ICI 118,551) antagonists gave estimates of the proportion of ₁- and ₂-adrenoceptors present in rat atria. Right atria contained 67±4.2% ₂-adrenoceptors and 33±4.2% ₂-adrenoceptor, while left atria contained 67±2.8% ₁- and 33±2.8% ₂-adrenoceptors. Increases in the rate of spontaneously beating right atria and the force of electrically driven left atria caused by-adrenoceptor agonists were also measured. pA₂ values for non-subtype selective-adrenoceptor antagonists in inhibiting isoprenaline-induced increases in rate and force were highly correlated withK _D values determined for specific¹²⁵IPIN binding. pA₂ values for ₁- and ₂-selective antagonists in inhibiting isoprenaline-induced increases in rate and force correlated well with the pK _D values of these drugs in binding to ₁-adrenoceptors, but not with the pK _D values in binding to ₂-adrenoceptors. Dose-response curves for stimulation of both rate and force by the ₂-selective agonists procaterol and zinterol were shifted to a much greater extent by selective blockade of ₁-adrenoceptors with metoprolol than by selective blockade of ₂-adrenoceptors with ICI 118,551, suggesting that these compounds caused their effects by activating ₁-adrenoceptors. These results suggest that ₁- and ₂-adrenoceptors coexist in both left and right atria of rat heart in approximately a 21 ratio, however only ₁-adrenoceptors mediate the chronotropic and inotropic effects of-adrenoceptor agonists.Supported by a grant from the American Heart Association — Georgia Affiliate     

股浅静脉戴戒术治疗原发性下肢深静脉瓣膜功能不全

目的 用股浅静脉戴戒术治疗原发性下肢深静脉瓣膜功能不全。方法 本文应用股浅静脉戴戒术治疗原发性下肢深静脉瓣膜功能不全34例,并应用无创性光电容积描记（PPG）结合临床症状改善状况对手术疗效进行评估。结果 手术前后静脉返流时间（VRT）有显著差异（P＜0．01）,临床症状改善。结论 股浅静脉戴戒术是治疗下肢深静静脉瓣膜功能轻度不全的有效方法,PPG检查结合临床改善程度是判断手术疗效更有效的方法。     

宫颈环扎术并发症

宫颈环扎术是治疗宫颈机能不全的唯一有效方法,其并发症发生率低,相关报道少,严重并发症罕见。最常见的并发症包括胎膜早破、绒毛膜羊膜炎、子宫内膜炎、围手术期出血、宫颈裂伤、环扎线或环扎带移位等,少见的并发症有膀胱宫颈瘘、输尿管宫颈瘘等,经阴道环扎的并发症较经腹环扎多。并发症的发生率因宫颈环扎的时机及适应证的不同而异。并发症常随孕周的增加及宫颈的扩张而增多,当胎膜破裂或宫颈扩张时行环扎术会增加并发症的发生风险。故应严格掌握适应证与禁忌证,选择适合的手术时机。已证明宫颈环扎的穿刺点和环扎带的位置直接影响妊娠结局,环扎带越接近宫颈内口效果越好。宫颈环扎后一般要限制体力活动,适当卧床休息,若子宫的敏感性增高给予孕酮和保胎药物,有感染病史及感染迹象者给予抗生素,重视阴道感染的筛查与治疗,密切监测母胎情况,关注宫颈环扎可能出现的并发症。开腹或腹腔镜环扎需剖宫产分娩,如有产兆,应即刻施术,避免发生宫颈裂伤或子宫破裂。     

Comparison of elective and empiric cerclage and the role of emergency cerclage

We describe the maternal, obstetric, and neonatal outcomes of patients undergoing elective, empiric, and emergency cervical cerclage at our institution in an attempt to determine predictive factors for adverse perinatal and maternal outcomes. A retrospective chart review was conducted on patients who underwent cervical cerclage placement over a 7-year time span. Of 55 charts, 40 contained complete peripartum data satisfactory for review; 7 elective, 15 empiric, and 18 emergency cerclages were analyzed. There was no perinatal mortality in the elective group, and 5/7 patients delivered at term. The empiric population experienced a 20% neonatal mortality; 6/15 gestations progressed to term. The perinatal mortality was 44% in the emergency group and 2/18 patients delivered at term. Relative to neonatal outcome, elective cerclage was statistically significantly better than emergent cerclage; there was no statistically significant difference between the elective and empiric groups nor between the empiric and emergent groups. This relatively small series with a large number of variables appeared to favor an elective procedure rather than an empiric one. Although emergent cerclage was associated with only a 56% neonatal survival, it did have value in some patients.     

Effect of nasal speaking valve on speech intelligibility under velopharyngeal incompetence: a questionnaire survey

Velopharyngeal incompetence is known as a contributing factor to speech disorders. Suwaki et al. reported that nasal speaking valve (NSV) could improve dysarthria by regulating nasal emission utilising one‐way valve. However, disease or condition which would be susceptible to treatment by NSV has not been clarified yet. This study aimed to evaluate the effect of NSV by questionnaire survey using ready‐made NSV. Subjects were recruited through the internet bulletin, and NSV survey set was sent to the applicant. Sixty‐six participants, who agreed to participate in this study, used NSV and mailed back the questionnaire which included self‐evaluation and third‐party evaluation of speech intelligibility. Statistical analysis revealed that the use of NSV resulted in significant speech intelligibility improvement in both self‐evaluation and third‐party evaluation (P < 0·01). Regarding the type of underlying disease of dysarthria, significant effect of NSV on self‐evaluation of speech intelligibility could be observed in cerebrovascular disease and neurodegenerative disease (P < 0·01) and that on third‐party evaluation in neurodegenerative disease (P < 0·01). Eighty‐six percent of subjects showed improvement of speech intelligibility by shutting up nostrils by fingers, and the significant effect of NSV on both self‐evaluation and third‐party evaluation of speech intelligibility was observed (P < 0·001). From the results of this study, it was suggested that NSV would be effective in cerebrovascular disease and neurodegenerative disease, as well as in subjects whose speech intelligibility was improved by closing nostrils.