Synthetic substrates in the histochemical demonstration of intestinal disaccharidases

Summary The splitting of 6-Br-2-naphthyl-, -naphthyl-, and 4-Cl-5-Br-3-indolyl-glycosides which proved useful for the assessment of cytological localization of intestinal enzymes in previous studies was investigated using isolated human and rat intestinal disaccharidases as a source of enzyme activities.Previous findings based on histochemical studies were confirmed and extended. 6-Br-2naphthyl-D-glucoside is cleaved by glucoamylase and sucrase-isomaltase. The participatio of trehalase in splitting of this substrate is very low and can be neglected. The mentioned -glucosidases are responsible for the brush border staining of enterocytes with this substrate when unfixed cold microtome sections are used. Even when a differential heat inactivation of sucrase-isomaltase and of glucoamylase occurs during paraffin embedding (so that the staining in paraffin sections is due mostly to glucoamylase) the use of natural substrates is desirable for a more precise assessment of sucrase-isomaltase activity (but without the possibility of a correct localization).4-Cl-5-Br-3-indolyl--D-fucoside is the substrate of choice for the demonstration of lactase. Even when this substrate is split also by hetero--galactosidase and by acid (lysosomal) -galactosidase these activities do not disturb the histochemical demonstration of lactase. If however some doubts arise, the inhibition with p-Cl-mercuribenzoate (2 · 10^–4 M) is to be emloyed (lactase activity is not inhibited). Due to a low K_m and a high V_max of indolyl-fucoside and due to its extreme stability in solution (which enables to use the substrate solution repeatidly) this substrate is suitable in routine practice even though it is expensive. -naphthyl- and 4-Cl-5-Br-3-indolyl--D-glucosides are split by lactase and -glucosidase. Due to the fact that the mutual delineation of these activities is not easy and that K_m an V_max for lactase are not so favourable as in the case of fucoside these substrates are not recommended for the assessment of lactase.6-Br-2-naphthyl--D-glucoside is the substrate of choice for the histochemical studies concerned with hetero--galactosidase and 4-Cl-5-Br-3-indolyl--D-galactoside for acid -galactosidase.     

Some further remarks "on testing hypotheses concerning standardized mortality ratios"

In testing the equality of any k standardized mortality ratios from p(?k) populations, Kupper and Kleinbaum (1971) pointed out that different test procedures are required for the two situations where the standard population is chosen independently of the p populations and where the standard is formed by pooling all p populations. Unfortunately, the test they propose for the latter situation is applicable only when k = p. The purpose of this paper is to describe an alternative procedure based on the general theories of Wald (1943) and Neyman (1949) which can be used if the standard is a pooled one even when k < p.     

An improved histochemical method for the demonstration of disaccharidases with natural substrates

Summary A simple histochemical method for the demonstration of disaccharidases is described. The medium consists of natural disaccharides (as substrates) and glucose oxidaseperoxidase-3,3-diaminobenzidine tetrahydrochloride (as the detecting agent) buffered to pH 6.0 with 0.05 M citric acid phosphate buffer in 1/2% agar gel. This method which enables the localization of disaccharidases on the histological level is very suitable for the routine assessment of activities of disaccharidases in enterobiopsies.     

Further explanatory remarks concerning the chemical mechanics of cell-division

Summary When oil-droplets are submerged by the addition of chloroform to the oil and sufficiently alkaline threads be brought in contact with a sufficient proportion of an equatorial circumference, division of the droplets into two occurs.In cell-division the cleavage furrow is a region of low superficial tension, the poles of the egg are regions of high superficial tension.Bütschli andMcClendon's view to the contrary is shown to involve a contradiction of the laws of molecular attraction in liquids.McClendon's evidence in support of his hypothesis has been shown to be fallacious.

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Zusammenfassung Werden öltröpfchen durch Zusatz von Chloroform zum öl zum Untertauchen und genügend alkalische Fäden mit einem ausreichenden Teile ihres Äquatorialumfanges in Berührung gebracht, so tritt Zweiteilung des Tröpfchens ein.Bei der Zellteilung ist die Teilungsfurche ein Bezirk niedriger Oberflächenspannung, die Eipole stellen Bezirke hoher Oberflächenspannung dar. Es wird gezeigt, daßBütschlis undMcClendons gegenteilige Ansicht einen Widerspruch gegen die Molekularattraktions-Gesetze in Flüssigkeiten involviert.McClendons Beweis zur Stütze seiner Hypothese wird als auf einem Irrtum beruhend nachgewiesen.

     

Critical remarks concerning the validity of the mitscherlich effect law

Summary A criticism is made of the evaluation of the Mitscherlich Effect Law on the basis of more than 27000 field experiments with graded amounts of fertilizers by Mitscherlich and Gericke. Accidental errors are eliminated to a large degree by the use of large numbers of field tests. According to these investigators (also Willcox) a very good confirmation of the law has been obtained, and the discrepancies found should be small and without any real significance.In contradiction to this view it is shown in the present paper that the discordance is important considering the large number of experiments. An exception should be made in the case of potatoes in which a confirmation of the Law was obtained. The principal cause of these discrepancies is probably the variability of the effect factorc of the fertilizer involved in single experiments.The constancy ofc=0.6 as for phosphate suggested by Mitscherlich was not confirmed for various crops. Better fitting results were obtained with different values ofc. These values varied in the case of phosphate between 0.35 for mangolds and 0.60 for barley with an average value for all crops of 0.44 ± 0.09.It is probable that the values ofc found are somewhat too high as a result of the residual effects involved in long term phosphate experiments.The determination of the amount of phosphateb in the soil gave rather discrepant results. The method of soil testing adopted by Mitscherlich based upon the assumption of a constant value ofc lacks a physiological foundation. Any advantage of this method over other conventional methods of soil testing is denied.

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Kritische Bemerkungen zur Gültigkeit des Mitscherlichschen Gesetzes der Wachstumsfaktoren

Zusammenfassung Es wird die Prüfung der Gültigkeit des Mitscherlichschen Gesetzes, wie diese anhand von 27000 Feldversuchen von Mitscherlich und Gericke durchgeführt wurde, kritisiert. Der Vorteil einer Benutzung größerer Zahlen von Versuchen ist daß zufällige Fehler eliminiert werden können. Nach der Meinung beider Förscher (auch Willcox) wurde eine recht befriedigende Bestätigung des Gesetzes erhalten. Die gefundenen Abweichungen würden klein und ohne wesentliche Bedeutung sein.Im Gegensatz zu dieser Auffassung wird aber gezeigt, daß die Abweichungen unter Berücksichtigung der großen Zahl der Versuche beträchtlich sind (Tabelle II). Eine Ausnahme macht nur die Kartoffel, mit welcher eine Bestätigung des Gesetzes gefunden wurde. Die Hauptursache der Abweichungen ist wahrscheinlich die Inkonstanz des Wirkungsfaktorsc in den verschiedenen Versuchen.Die Konstanz vonc=0.6, wie diese Mitscherlich als erwiesen betrachtet, konnte für verschiedene Gewächse nicht gefunden werden. Genauere Angleichung der Daten wurde mit wechselnden Werten fürc erhalten. Diese Werte lagen zwischen 0.35 für Futterrüben und 0.60 für Gerste, der mittlere Wert betrug 0.44 ± 0.09. Es ist aber wahrscheinlich daß die gefundenen Werte vonc bei den mehrjährigen Feldversuchen infolge der Nachwirkung der Phosphatdüngung mehr oder weniger zu hoch sind.Die Bestimmung der im Boden vorhandenen wirksamen Phosphorsäuremengeb ergab ziemlich auseinanderliegende Werte. Die Mitscherlichsche Methode der Bodenuntersuchung, welche sich auf die Annahme konstanter Wirkungsfaktoren stützt, entbehrt einer physiologischen Grundlage. Die Vorteile dieser gegenüber den chemischen Methoden werden verneint.

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Mit deutscher Zusammenfassung

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W. Stollenwerk in a recent paper⁵) criticizing the work of Mitscherlich and Gericke but employing different methods attained approximately similar results to those of the present paper.     

Some remarks on organization and structure

Self-organizing systems are defined as able to change their structure, according to need, within specific equivalence classes. Once hierarchical levels and their value functions are assigned, requirements of invariance under transformations within an equivalence class can be used as a principle to determine the population of each level. This program is carried out in complete detail, as an example, for a particular class of systems (called modular), for which it is shown that a full Thermodynamics can be constructed. Modular systems are compared with linguistic, monetary, and military organizations; they are found to describe exactly the empirical data available on monetary circulation over the world, and to offer other perhaps suggestive indications. The emerging picture is that of a development, for any such system, which alternates phases of evolution (changes of level occupation numbers) with phases of revolution (changes of level structure within the given equivalence class).