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 on the monocyte test]

The application of the monocyte test in the diagnostics of drug allergy is considered from a critical point of view. Further hospital application of the test and its evaluation are discussed.     

Some remarks concerning the histochemical detection of disaccharidases and glucosidases

Summary In the histochemical detection of the disaccharidases and glucosidases the reliability of methods with coupled oxidation of glucose (with various buffers, tetrazolium salts and concentrations of substrates, tetrazolium salts and PMS) and azo-dye methods with the postincubation as well as simultaneous azo-coupling in cryostat sections (unfixed, fixed with Baker's formol and acetone) and frozen sections after fixation in cold Bakers's formol and glutaraldehyde was tested. Various rat organs and human enterobiopsies were used. The methods were modified.Despite the fact that glutaraldehyde and formol fixation does not completely destroy enzyme activities splitting maltose, sucrose, trehalose and lactose (as it could be shown by a simple Glukophan test) the use of the fixed sections is not recommended. Activity of these enzymes is not completely structurally bound and a part of them escapes from the unfixed cryostat sections into the solutions used for rinsing or for incubation. Activities of these enzymes were demonstrated in the content of the rat jejunum as well. The results of the detection of disaccharidases with a coupled oxidation of glucose are dependent on buffer (type and pH), on the tetrazolium salt (type and concentration), on the concentration of phenazine methosulfate and of disaccharides, on the conditions during the incubation (temperature, anaerobic or aerobic conditions, aqueous or gel media) and on the type of sections. With all the substrates used (maltose, sucrose, trehalose and lactose) a positive reaction in the enterocytes (both of rat and human) and in the cells of convoluted tubules in rat kidney was obtained. With lactose the reaction was weak and irregular and could be obtained under anaerobic conditions only. A proximodistal gradient in the rat intestine was revealed. In the detection of lactose the use of galactose oxidase in combination with glucose oxidase decreased the intensity of the staining. In evaluating the validity of the localization the artifacts caused by the diffusion of disaccharidases and by the method with coupled oxidation of glucose were considered, the latter being their main source. By no means such artifacts could be avoided. The positive staining is revealed in the sites of the bound tetrazolium salt where it is contacted by the reduced PMS. No reaction can be obtained in sites lacking affinity for the tetrazolium salts even if they contained an active enzyme. The technique allows at the most the localization on the cellular but not intracellular level. The disaccharidase granules of Dahlquist and Brun are artifacts.When the sections are incubated individually with the described gel media or in the incubation chambers the amount of produced formazan may serve as a measure of the activity of the respective disaccharidase. Such technique proved to be of value in investigating the changes of activities of disaccharidases in the jejunum of patients with primary malabsorption syndrome. These activities were reduced in comparison with the normal jejunum.The limitations in localization of the postincubation azo-coupling methods for the deection of glucosidases and galactosidases are much the same as those of the methods with coupled oxidation of glucose. In addition to it the relative substrate specificity of the intestinal disaccharidases has to be considered, because identical enzymes may not be detected with synthetic and natural substrates. Using our new method with hexazo-p-rosaniline in the simultaneous azocoupling an improved localization of 6-Br-2-naphthyl--D-glucosidase was achieved. In the enterocytes the enzyme was localized in the microvillous zone and apical part of the cytoplasma.     

Taxonomic remarks concerning ostracods of the Ponto–Caspian Basin

Taxonomic revision of ostracods of the Pliocene–Pleistocene beds of the Caspian Basin from collections of the VNIGRI and analysis of published data on ostracods of the Ponto–Caspian Sea results in synonymization of 16 species names; one species is provided with a new combination, 40 identifications are improved, and 12 erroneous spellings of ostracod names by certain authors are revealed.     

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.