Interactions of small polypeptides with dimyristoylphosphatidylcholine monolayers: effect of size and hydrophobicity

The effects of size and hydrophobicity of small (molecular weights below 2,000) polypeptides on their predominantly hydrophobic interactions with a neutral phospholipid monolayer were studied. The changes in surface pressure were determined when various concentrations of Gly, Gly-Gly-Gly, -Ala, -Ala- -Ala- -Ala, -Ala-Gly-Gly-Gly-Gly, -Phe- -Leu- -Glu- -Glu- -Leu, adrenocorticotropic hormone fragments 1–10 (ACTH-(1–10)), porcine β-lipotropin, -endorphin and human fibrinopeptide A were injected under dimyristoylphosphatidylcholine (DMPC) monolayers at an initial surface pressure of 10 dyne/cm. In all cases, when peptides with the same number of residues are compared, the concentration needed to increase the surface pressure of the film by 1 dyne/cm was inversely related to its hydrophobicity. A reasonably good correlation was found to exist between the calculated free energy of transfer of a polypeptide from ethanol to water (a measure of its hydrophobicity) and its ability to increase the surface pressure of the DMPC film (a measure of the extent of its interaction with the neutral lipid monolayer).     

Differential Stripping: Determination of the Amount of Topically Applied Substances Penetrated into the Hair Follicles

The determination of penetration pathways of topically applied substances into the skin is the subject of several investigations. Recently, follicular penetration has become a major focus of interest. To date, a direct, non-invasive quantification of the amount of topically applied substance penetrated into the follicles had not been possible. The development of such a method was the aim of this study. Therefore, the advantages of both stripping techniques, tape stripping and cyanoacrylate skin surface biopsy, were combined and evaluated. Tape stripping was used to remove the part of the stratum corneum that contained the topically applied dye. Subsequently, the follicular contents were ripped off by cyanoacrylate skin surface biopsy. The combined method termed "differential stripping" was evaluated in vitro and in vivo , and the amount of topically applied fluorescent dye penetrated into the hair follicles was quantified after different penetration times. After 30 min, 5% of the recovered concentration of sodium fluorescein was found in the follicular infundibula, where it was still detectable after 48 h. Altogether, the results of this investigation revealed that differential stripping is a new method that can be used to study the penetration of topically applied substances into the follicular infundibula non-invasively and selectively.     

用化学发光自显影技术快速检测鸭沙门氏菌

应用我室建立的化学发光自显影技术检测鸭沙门氏菌。用酶标抗体与硝酸纤维素膜上固定的细菌结合,再同发光底物溶液作用,使X线胶片感光,根据胶片上的黑斑进行半定量,可检出100个菌。其检测特异性好,约2小时即可出报告。     

头低位限制活动对家兔主要脏器微血管壁通透性的影响

本文报导了用40只白色短毛家兔所做的动物模拟失重实验,得出各脏器微血管通透性的动态反应曲线。并用微循环研究方法,分析了模拟失重时各脏器微血管功能状态与微血管通透性之间的关系;阐述了各脏器微循环功能变化特点;并对变化机理作了初步探讨。     

Staple penetration and staple histological response for attaching an epimysial electrode onto the abdominal surface of the diaphragm using a laparoscopic approach

Background: Laparoscopic stapling was found to be a viable option for attaching epimysial electrodes onto the abdominal surface of the diaphragm. Stapling was preferable to suturing due to its simplicity and speed. Methods: Of the two staplers tested in this study, the Ethicon Endopath was preferred over the Autosuture Endo Hernia because the staples did not penetrate the diaphragm when an electrode tab thickness greater than 0.75 mm was used. Results: The thickness of the electrode tab was an important factor in determining staple penetration but large variation in penetration depth indicated that other factors may also play a role. An electrode tab thickness of 1.0–1.25 mm was suggested to minimize the risk of diaphragm perforation. Conclusions: The histological reaction to staples implanted up to 14 months was unremarkable, reflecting the safety of laparoscopic staples for permanently anchoring electrodes on the diaphragm. Received: 2 April 1996/Accepted: 12 June 1996     

人精子穿卵改良试验对不同生育状态男子生育力测定的价值

目的　本研究用一种经改良的人精子穿卵试验 (SPA)处理人精子 ,以探讨一种更简便、快速、经济 ,适合一般实验室要求的方法。方法　将精子体外获能液用磷酸氢二钠把pH值调理至 8.2± 0 .2 ;用普通隔水式恒温培养箱进行培养 ;对 75例不同生育状态男子生育力进行测定 (其中 2 5例有生育力男子 ;2 5例“原因不明”不育男子 ;及 2 5例输精管吻合术后 )。结果　 3种不同生育状态男子的SPA值分别是 (4 7.12± 9.92 ) % ;(2 1.73± 9.91) % ,及 (2 8.0 4± 9.91) %。前两者在统计学上有显著差异 ,(P<0 .0 1) ;后两者在统计学上无明显差异 (P >0 .0 5 )。结果表明经用改良的精子获能液并在普通恒温培养箱培养后精子的活率和活力都有较大的提高 ,这有利于精子的长期获能及提高精子的穿透能力。结论　本研究提示改良后的人精子穿卵试验处理精子确实更简便、快速、经济 ,适合一般实验室要求 ,便于推广。     

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.     

宫颈粘液中白细胞增多与不孕的关系研究

我们对本地区因不孕而就诊的220对夫妇作精子-宫颈粘液穿透试验(SCMPT),同时,作了宫颈粘液涂片并计数每100个鳞状上皮中的白细胞数,观察这两者的相关关系.结论:随着宫颈粘液中的白细胞数增加,穿透优良的比率下降(P<0.005).因而体外SCMPT评分结果与宫颈粘液中的白细胞增多相关.