EFFECTS OF BKCa CHANNELS ON THE REDUCTION OF CYTOSOLIC Ca2+ IN cGMP-INDUCED RELAXATION OF GUINEAPIG TRACHEA

1. In order to examine the mechanisms of cGMP-induced relaxation in airway smooth muscle, the effects of atrial natriuretic peptide (ANP) and 8-brom cGMP on muscle tone were studied by measuring isometric tension, while the effects on cytosolic Ca²⁺ concentrations were studied by measuring the spectra of fura-2 loaded in guinea-pig tracheal strips. 2. Atrial natriuretic peptide and 8-brom cGMP caused a concentration-dependent inhibition of spontaneous tone in the guinea-pig trachea. The relaxant effects of these agents on spontaneous tone were markedly suppressed in the presence of iberiotoxin (IbTX), a selective inhibitor of large-conductance Ca²⁺-activated K⁺ (BKca) channels. Iberiotoxin (30 nmol/L) markedly affected the maximal effect induced by ANP and 8-brom cGMP and augmented EC₇₀ values for ANP and EC₅₀values for 8-brom cGMP approximately 27- and 17-fold, respectively. The inhibitory effects of IbTX on relaxation induced by these agents were diminished in the presence of 1 μmol/L nifedipine, an antagonist of voltage-operated Ca²⁺channels (VOCC). 3. The inhibitory action of ANP and 8-brom cGMP on spontaneous tone was not affected by the presence of 10 μmol/L glibenclamide, an inhibitor of ATP-sensitive K⁺ channels, and 100 nmol/L apamin, an inhibitor of small-conductance Ca²+-activated K⁺ channels. When these agents were applied to tissues precontracted by high (40mmol/L) K⁺, the relaxant effects of these agents markedly diminished. 4. The extracellular Ca²⁺-dependent contraction was inhibited in the presence of 0.3 μmoI/L ANP or 0.1 mmol/L 8-brom cGMP. Concentration—response curves to extracellular Ca²⁺ (0.03—2.4 mmol/L) were markedly diminished by exposure to these agents. The maximal effect induced by extracellular Ca²⁺ was affected by these agents. 5. Atrial natriuretic peptide caused an inhibition of spontaneous tone accompanied by a reduction in the intracellular Ca²⁺ concentration. In the presence of IbTX, the elimination of both muscle tone and cytosolic Ca²⁺ by ANP was suppressed. 6. We conclude that ANP and 8-brom cGMP activate BKca channels and that the inhibition of Ca²⁺ influx through VOCC, mediated by BKca channel activation, may be involved in cGMP-dependent bronchodilation.     

Effects of recombinant humanen dothelial-derived interleukin-8 on hemorhagic shock in rats

目的：研究重组人内皮细胞衍生的白细胞介素－８（ＩＬ８）对失血性休克的作用．方法：大鼠股动脉放血至ＭＡＢＰ５３２ｋＰａ，维持９０ｍｉｎ，复制晚期失血性休克模型．输血后，静脉注射ＩＬ８２５０μｇ·ｋｇ－１．放免法测定血浆ＥＴ１和６ＫＰＧＦ１α含量．结果：给予ＩＬ８后，ＭＡＢＰ显著提高，休克状态改善，２ｈ存活率相应提高；休克晚期血浆ＥＴ１水平比正常明显升高（２１±４ｖｓ８２±１８ｎｇ·Ｌ－１，Ｐ＜００１），血浆６ＫＰＧＦ１α含量明显降低（１０７±１２ｖｓ１５７±１１ｎｇ·Ｌ－１，Ｐ＜００１）．ＩＬ８显著降低血浆ＥＴ１水平（１０±４ｎｇ·Ｌ－１，Ｐ＜００１），提高血浆６ＫＰＧＦ１α含量（３６８±１６ｎｇ·Ｌ－１，Ｐ＜００１）．结论：ＩＬ８具有较好的抗休克作用．     

免疫抑制因子对佐剂关节炎的影响

目的；研究免疫抑制因子对佐剂关节炎发病的影响。方法：检测对照组与实验组对正常小鼠淋巴细胞转化的影响。结果：脑室注射ＩＬ１的关节炎大鼠在第０、７、１４、２８、３５ｄ的血清具有明显的抑制淋巴细胞转移化的作用。关节炎症状加重，病程延长。结论：免疫抑制蛋白可能参与佐剂关节炎的发病，有可能是造成关节炎的原因之一。     

单波长荧光分光光度计测定细胞内Ca^2＋浓度的方法探索

在使用单波长荧光分光光度计测定细胞内游离钙浓度时，通过快速（４～６ｓ）手动转换激发波长（ＥＸ），分别测定ＥＸ３４０和３８０ｎｍ时的荧光强度变化，并计算出３４０ｎｍ与３８０ｎｍ时的荧光强度比率（Ｒ），然后也采用双波长荧光分光光度计测定细胞内Ｃａ２＋浓度的计算公式计算细胞内游离钙浓度。结果显示单波长荧光分光光度计按比例法测得的细胞内游离Ｃａ２＋浓度与使用双波长荧光分光光度计测得的结果相似。     

Pharmacological properties of Ca2+-activated K+ currents of ramified murine brain macrophages

Using the whole-cell configuration of the patch clamp technique, calcium-activated potassium currents (I_K,Ca) were investigated in ramified murine brain macrophages. In order to induce I_K,Ca the intracellular concentration of nominal free Ca²⁺ was adjusted to 1μM. The Ca²⁺-activated K⁺ current of brain macrophages did not show any voltage dependence at test potentials between –120 and +30mV. A tenfold change in extracellular K⁺ concentration shifted the reversal potential of I_K,Ca by 51mV. The bee venom toxin apamin applied at concentrations of up to 1μM did not affect I_K,Ca. Ca²⁺-activated K⁺ currents of ramified brain macrophages were highly sensitive to extracellularly applied charybdotoxin (CTX). The half-maximal effective concentration of CTX was calculated to be 4.3nM. In contrast to CTX, the scorpion toxin kaliotoxin did not inhibit I_K,Ca at concentrations between 1 and 50nM. Tetraethylammonium (TEA) blocked 8.0% of I_K,Ca at a concentration of 1mM, whereas 31.4% of current was blocked by 10mM TEA. Several inorganic polyvalent cations were tested at a concentration of 2mM for their ability to block I_K,Ca. La³⁺ reduced I_K,Ca by 72.8%, whereas Cd²⁺ decreased I_K,Ca by 17.4%; in contrast, Ni²⁺ did not have any effect on I_K,Ca. Ba²⁺ applied at a concentration of 1mM reduced I_K,Ca voltage-dependently at hyperpolarizing potentials. Received: 17 January / Accepted: 5 May 1997     

盘龙七片治疗不稳定性冠心病心绞痛临床观察

对５８例不稳定性冠心病心绞痛患者，用盘龙七片（３８例）及复方丹参片（２０例）治疗，观察治疗前后心电图ＳＴ段，血液流变学及临床症状的变化，结果：盘龙七片组心电图ＳＴ段的缺血变化明业优于复方丹参片组（Ｐ〈０．０１），血浆粘度及纤维蛋白原下降亦明显（Ｐ〈０．０５或Ｐ〈０．０１），结论：盘龙七片虽是一种抗风湿，骨伤的中成药，但同样对治疗不稳定性冠心病心绞痛有一定的疗效。     

Marital Functioning in Early Versus Late-Onset Alcoholic Couples

Current knowledge about alcohol and marital functioning is limited by restrictive sample selection, inattention to the literature on individual-based alcoholic subtypes, and lack of research linking individual differences among alcoholics to marital functioning. The present study was designed to study marital functioning of alcoholics in light of current alcohol typologies. Subjects were part of a larger study on conjoint treatment of alcoholic males and their female partners. Four typologies—including Type 1/2, In-Home/Out-of-home, SteadyIEpisodic, and EarlyILate Onset—were tested for replicability and discriminant validity before linking them to marital functioning. Discriminant validity was found only for the Early (59%)-versus Late (41 %)-Onset typology; thus, further analyses linked only this typology with marital functioning. At baseline, Early-Onset couples reported more marital instability, and the females in these couples were more distressed. During treatment, Early-Onset couples reported higher daily marital satisfaction than Late-Onset couples. Regardless of age of onset, males reported higher marital satisfaction than their spouses during treatment, but their satisfaction did not increase during treatment. Female partners' marital satisfaction increased during treatment. Female partners of Late-Onset males reported particularly low marital satisfaction during treatment. Parsing the sample according to the early-/late-onset typology yielded different predictors of marital satisfaction for males and females within each subtype. For female partners of Early-Onset alcoholics, psychological distress unrelated to her pattner's drinking severity was most associated with her own marital satisfaction, whereas marital adjustment of female partners of Late-Onset alcoholics was most associated with the male's level of perceptual accuracy regarding her needs. This pattern was reversed for the males; marital adjustment of Early-Onset alcoholics was most associated with his partner's perceptual accuracy of his needs, whereas marital functioning of Late-Onset alcoholics was best accounted for by his own psychological distress.     

An XPS and SEM evaluation of six chemical and physical techniques for cleaning of contaminated titanium implants

The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed.     

Influence of Preparation Factors on the Sustained Release of Nifedipine from Eudragit RL/RS Microspheres

用乳剂—溶剂挥发法制备硝苯地平的丙烯酸树脂缓释微球。微球中药物的释放速度随丙烯酸树脂ＥｕｄｒａｇｉｔＲＬ／ＲＳ比率的增加以及制备时搅拌速率的增加而增大，随内相聚合物浓度的增加及微球粒径的增加而减小，释药５０％所需时间与微球粒径呈良好线性。微球的释药速率也随药物含量的增加（从４．２％到１６．７％）而增大，并快于药物结晶的溶解速率，但药物含量达２６．６％时，微球释药速率明显下降并低于药物结晶的溶解速率。用差热分析和Ｘ射线衍射分析证明，药物含量为４．２，９．４和１６．７％的微球中药物完全是以非晶态分散的，而含药２６．６％的微球中有药物结晶存在。不同微球释药低于７０％时，释放方式均符合Ｈｉｇｕｃｈｉ时间平方根方程。