Stability of some bradykinin analogues against kininase II (author's transl)]

Some analogues of bradykinin, especially with replacements by other amino acids of phenylalanine in position 8, have been investigated for enzymatic stability against kininase II from rat duodenum microsomes and rat uterus plasma membranes, respectively. As compared with bradykinin, two of the analogues, [8-erythro-beta-phenylserine]- and [8-erythro-alpha-Amino-beta-phenylbutyric acid]-Bradykinin were stable to enzymatic degradation. Therefore, the latter may be used for studies in hormone-receptor interaction.     

柳杉树轮δ~(13)C与气候要素的分析与应用

<正>对采自气候为非限制性因子地区的柳杉树轮稳定碳同位素比 δ１３ Ｃ进行气候响应分析。用排除法消除大气二氧化碳中δ１３Ｃ的变化对柳杉树轮δ１３Ｃ变化的影响后,建立残差年序列ＲＥ,并结合西天目山气象站的气象记录,分析了树轮δ１３Ｃ年序列对气候要素的响应。结果表明：西天目山地区树轮 δ１３Ｃ的高频振荡与 １１、１２月最高气温的平均值,１、２、３月降水总和以及６、７月降水总和显著相关,在一定程度上反映了东亚季风对该区的影响大小。可见气候非限制性因子地区树轮稳定碳同位素组成年序列同样可以作为气候变化指针。     

Stabilität verschiedener Bradykininanaloga gegen kininase II

Summary Some analogues of bradykinin, especially with replacements by other amino acids of phenylalanine in position 8, have been investigated for enzymatic stability against kininase II from rat duodenum microsomes and rat uterus plasma membranes, respectively. As compared with bradykinin, two of the analogues, [8-erythro--phenylserine]-and [8-erythro--Amino--phenylbutyric acid]-Bradykinin were stable to enzymatic degradation. Therefore, the latter may be used for studies in hormone-receptor interaction.

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Mitteilung: Untersuchungen an bradykininbindenden Zellfraktionen.

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Frau Dr.M. P. Filatova aus dem Shemyakin-Institut für Bioorganische Chemie der Akademie der Wissenschaften der UdSSR, Moskau, danken wir für ihre Mitarbeit bei der Erstellung der Arbeitskonzeption. Für die Präparation der Membranen sei FrauT. Jankova, HerrnC. Liebmann und HerrnH. Steinmetzger herzlich gedankt. Wir danken Frl.R. Raspe, Frl.B. Schilling und FrauI. Agricola für die gute technische Mitarbeit bei der biologischen Wertbestimmung und der Präparation der Membran — bzw. Mikrosomenfraktion.     

Physiology: Dynamic instabilities in the inflating lung

In lung diseases such as asthma, expiratory flow becomes limited, airways can collapse and the vital exchange of gases is compromised. Here we model the inflation of collapsed regions of the lung during inspiration in terms of avalanches propagating through a bifurcating network of airways, and find that the accompanying cascade of dynamic pressure instabilities -- avalanche 'shocks' -- manifests as negative elastic resistance of the lung. Our analysis of this apparent thermodynamic paradox provides a better understanding of aeration in the deep regions of the lung, which may find application in medical conditions in which gas exchange is impaired.