Determination of opipramol in human plasma by high-performance liquid chromatography with photometric detection using a cyanopropyl column

A high-performance liquid chromatographic method is described for the determination of opipramol in human plasma. Opipramol was extracted into tert.-butylmethyl ether, separated on a cyanopropyl silica column and detected at 254 nm. Imipramine was used as internal standard. The limit of quantitation was 250 pg/ml using 1.5 ml plasma. Precision was better than 9%, inaccuracy less than 8%. The assay is more sensitive than previously published methods, and it has been applied to the analysis of plasma samples from a pharmacokinetic study.     

Ethylene effects on growing and gravireacting maize root segments

The effects of ethylene pretreatments (500 nl/l for 1 h) and treatments (100 nl/1 to 1000 nl/l for 6 h) on elongation and gravireaction of apical maize root segments were tested in light and in the dark. Ethylene was found to affect weakly root elongation and gravireaction, but to induce strong curvatures for root growing vertically.     

Die Ultrastruktur des Juxtaglomerulären Apparates des Meerschweinchens

Zusammenfassung Der Beweis für das Vorkommen von Sekretgranula in den epitheloiden Zellen des Meerschweinchens ist bisher von keinem Autor erbracht worden. Ihre Abwesenheit ist um so erstaunlicher, als die Renin-Aktivität in der Niere dieses Tieres etwa 1/10 der der Ratte mit ihren stark granulierten Epitheloidzellen beträgt und die des Menschen sogar übertrifft. In unserem Untersuchungsgut finden wir hin und wieder einige wenige, wahrscheinlich Renin enthaltende Granula (Abb. 1–4). Anscheinend erfolgen Synthese und Ausscheidung des Enzyms im gleichen Rhythmus; zu einer geringgradigen Speicherung kommt es offenbar nur unter bestimmten funktionellen Bedingungen.Die Goormaghtighschen Zellen (Abb. 5) zeigen kein besonderes auffälliges artspezifisches Verhalten.An der Macula densa wird erstmals eine starke Erweiterung sowohl der intracytoplasmatischen Einfaltungen des basalen Plasmalemms — des basalen Labyrinthes — als auch der Interzellularspalten beschrieben (Abb. 6–9). Diese oberhalb der Basalmembran gelegenen Pseudovakuolen sind somit extrazellulär und möglicherweise als morphologisches Äquivalent einer starken Reabsorptionstätigkeit zu deuten. Es ist zur Zeit noch nicht entschieden, ob sie mit der von uns angewandten Präparationstechnik auch bei anderen Tieren und beim Menschen darstellbar sind.

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Summary The presence of secretory granules in the epithelioid (juxtaglomerular) cells in the media of the preglomerular portion of the afferent arterioles in the kidney of the Guinea pig has not been proven by any author until now. The absence of these granules is all the more astonishing in view of the fact that the renin activity of this animal is about 1/10 of that of the rat — with its highly granulated cells — and even surpasses that of humans. In our inbread strain rare granules likely containing renin can be found from time to time (Fig. 1–4). Apparently, the synthesis and extrusion of the enzyme takes place with the same rhythm; a very low degree of accumulation occurs probably only under certain functional conditions.The Goormaghtigh Cells (Fig. 5) show no noticeable differences specific for the Guinea pig. In the Macula densa highly developed enlargements of the basal infoldings of the plasma membrane — basal labyrinthe — as well as of the intercellular spaces are described for the first time (Fig. 6–9). These enlargements (Pseudovacuoles), situated above the basement membrane, are extracellular and can possibly be interpreted as the morphological equivalent of a high degree of absorption activity. At the present time it has not been decided, if, using the authors' technique, these enlargements can be demonstrated in other animals and humans.

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In Zusammenarbeit mit dem Pharmakologischen Institut der Universität Lausanne und mit Unterstützung durch die Fritz Hoffmann-La Roche-Stiftung zur Förderung wissenschaftlicher Arbeitsgemeinschaften in der Schweiz.     

The PROSITE database, its status in 1995.

The PROSITE database consists of biologically significant patterns and profiles formulated in such a way that with appropriate computational tools it can help to determine to which known family of proteins (if any) a new sequence belongs or which known domain(s) it contains.     

Concentrations of nutritional and trace elements in needles of Norway spruce (Picea abies [L.] Karst.) as functions of the needle age class

The endogenous concentrations of the essential elements Ca, Cl, Cu, Fe, K, Mg, Mn, N, P and Zn, and of the nonessential elements Al, As, Ba, Br, Co, Cr, Cs, Hg, I, La, Na, Rb, Sb, Sc, Si and Sr were determined in 5 successive needle age classes. 40 mature spruce trees from 6 different sites were investigated individually. A given element usually shows smooth changes with the needle age class t. Trees on a given site usually have a similar dynamic behaviour. The same holds for the different site means. The concentrations can be approximated by functions c=f(t). Three different types of functions are required to describe the dynamic behaviour of 3 groups of elements that increase with t, and one for the elements that decrease with t. A given element usually can be described by the same type of function at all sites, even if its concentration differs widely. Exceptions are Mn, Co and Zn, which change from a decreasing function at low concentrations to an increasing function at high concentrations. Further irregulatities are found at some sites with Ca, Sr and Ba. These findings are corroborated by a multivariate statistical analysis.     

Ultrastructural and morphometric aspects of the juxtaglomerular apparatus in the monkey kidney

Summary The authors describe the ultrastructure of the juxtaglomerular apparatus in five adult male Cebus apella monkeys and communicate morphometric data of the macula densa.In comparison with several species of rodents examined before, the macula cells of the monkey contain many more mitochondria and possess a particularly thick basal membrane. The relative volume of the nuclei is slightly smaller than in rodents.The Goormaghtigh cells of the monkey resemble those of the other animals investigated.The epithelioid (or juxtaglomerular) cells do not contain secretory granules. This observation reminds one of the behavior of the epithelioid cells of guinea pigs.Dedicated to Professor Dr. med. G. Petry (Marburg/Lahn) on the occasion of his 65th birthdayThe authors wish to thank Professor Dr. G. Peters, Head of the Institute of Pharmacology, and Professor Dr. F. Roch-Ramel for kindly having provided the monkey kidneys