Co-existence of immunoreactivity to anti-dopamine,anti-serotonin and anti-vasotocin in the cerebral giant neuron of the pond snail Lymnaea stagnalis

Summary Consecutive sections of certain neurons in the central ganglia of the pond snail Lymnaea stagnalis appear to be immunoreactive to anti-dopamine and anti-serotonin. The Cerebral Giant Neurons stain in addition with antivasotocin. The observations indicate the presence of two biogenic amines within the same neuron and in addition their co-existence with a biologically active peptide.     

F-actin organization influences the osmotic reactions of animal cells

The resistance of chick embryo fibroblasts (CEF) and Ehrlich ascites tumour (EAT) cells to the disruption in strongly hypotonic medium was measured in the presence or absence of cytochalasin B. The osmotic resistance of CEF spread on solid substratum was much higher than that of CEF suspended in a fluid medium. Cytochalasin B decreased the osmotic resistance of spread CEF, but not of suspended CEF or EAT cells. These data demonstrate that not only the properties of cell membrane, but also the organization of actin filaments determines the osmotic reactions of cells.     

Ecdysteroids regulate the release and action of eclosion hormone in the tobacco hornworm, Manduca sexta (L.)

The relationship between the ecdysteroid titre and eclosion hormone was explored for the pupal and adult ecdyses of Manduca sexta. Ecdysteroid treatment late during either moult caused a dosedependant delay in the time of ecdysis. Sensitivity to exogenous steroid treatment dropped off as the respective moults neared completion and in both cases coincided with the time of the low point in the endogenous ecdysteroid titre. It was concluded that an ecdysteroid decline is a normal prerequisite for the ecdyses of both stages. The steroid drop is important for two aspects of the eclosion hormone system: it causes target tissues to become sensitive to the peptide and it is a prerequisite for the subsequent release of eclosion hormone itself. Thus, the dual action of the declining ecdysteroid titre insures that when eclosion hormone is released, the tissues will be competent to respond to it.     

Der cytochemische Nachweis von Prolin-Dehydrogenasen,Acetaldehyd-Dehydrogenasen und Dihydroliponsäure-Dehydrogenase in den Zellen vonSaccharomyces cerevisiae

Summary Using the tetrazolium salt Nitro-BT, the following dehydrogenases can be demonstrated cytochemically in the cells ofSaccharomyces cerevisiae: (1)Proline dehydrogenase activity: it cannot be decided whether the formazan production is a result of L-proline: NAD(P)-2-oxidoreductase (E.C. 1.5.1.1) or of L-proline:NAD(P)-5-oxidoreductase(E.C. 1.5.1.2); (2)Aldehyde dehydrogenase activity: using the coenzymes NAD and NADP and the activators KCl and MgCl₂, different reaction pictures are obtained which led to the conclusion that aldehyde: NADP oxidoreductase (E.C. 1.2.1.4) and aldehyde: NAD(P) oxidoreductase (E.C. 1.2.1 5) can be demonstrated seperately; (3)Dihydrolipoic dehydrogenase (E.C. 1.6.4.3): an exactly controlled pH level (pH 6.0) of the complete incubation medium is an essential prerequisite for the specificity of the reaction. The formation of filamentous formazan deposits can be interpreted as the expression of the mitochondrial localization of the enzyme.Zusammenfassung In den Zellen vonSaccharomyces cerevisiae lassen sich mit Hilfe des Tetrazoliumsalzes Nitro-BT cytochemisch nachweisen: 1. eineProlin-Dehydrogenasen-Aktivität, wobei nicht entschieden werden kann, ob die Formazanbildung durch L-Prolin: NAD(P)-2-Oxydoreduktase(E.C. 1.5.1.1) oder durch L-Prolin: NAD(P)-5-Oxydoreduktase(E.C. 1.5.1.2) hervorgerufen wird; 2. eineAldehyd-Dehydrogenasen-Aktivität: durch Einsatz der Coenzyme NAD und NADP sowie der Aktivatoren KCl und MgCl₂ erhält man unterschiedliche Reaktionsbilder, so daß die Annahme gerechtfertigt erscheint, daß hiermit Aldehyd: NADP-Oxydoreduktase(E.C. 1.2.1.4) und Aldehyd: NAD(P)-Oxydoreduktase (E.C. 1.2.1.5) getrennt nachweisbar sind; 3. dieDihydroliponsäure-Dehydrogenase (NAD-H₂:Lipoamid-Oxydoreduktase, E.C. 1.6.4.3): bei diesem Enzymnachweis ist eine exakte Einstellung des pH-Wertes des Mediums auf 6,0 die Voraussetzung für die Spezifität. Die Bildung länglicher Formazanablagerungen in den meisten Zellen deutet auf die mitochondriale Lokalisation des Enzyms hin.

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Frau Prof. Dr. B.Haccius danke ich für die großzügige Unterstützung bei der Durchführung dieser Untersuchungen. Die Brotfabrik Grahamhaus Studt KG., Bad Kreuznach, stellte einen Arbeitsplatz zur Verfügung, wofür ich auch an dieser Stelle danken möchte.     

Application of non-radioactive methods of DNA detection in analysis of human genetic disorders

We have applied two non-radioactive methods for detection of unique sequences in human genome: 1 polymerase chain reaction, 2 hybridization with digoxigenin-deoxyuridine 5-triphosphate labeled probes. With the polymerase chain reaction technique we were able to amplify short segments of genes coding for coagulation factors VIII and IX. Electrophoretical analysis of products of polymerase chain reaction enabled us to detect deletions causing hemophilia A or B. To analyse deletions in dystrophin gene, the most frequent cause of Duchenne muscular dystrophy, we have amplified several different fragments of this gene simultaneously. We have studied restriction fragment length polymorphism closely linked to the cystic fibrosis locus with digoxigenin-deoxyuridine 5 -triphosphate labeled probe p3.11 with sensitivity comparable to methods involving the use of radioisotopes.     

The frequency of mutations in exon 11 of the CF gene in Polish cystic fibrosis patients.

Results of mutation analysis in exon 11 of the CF gene have been presented. Using the SSCP technique 18 mutations (of four different types) were detected in cystic fibrosis patients of Polish origin. Thus, we were able to detect in exon 11 about 10% of all CF mutations occurring in the affected population examined.     

Generation of long-term human cytolytic cell lines with persistent natural killer activity

Human cell lines maintained by in vitro stimulation with the HLA-A, B-negative, DR-positive, Epstein Barr virus-transformed, lymphoblastoid cell line Daudi in the presence of conditioned medium demonstrated significant NK activity for over 6 wk in continuous culture. These cells lyse K562 and a broad panel of lymphoblastoid cell lines but do not lyse normal peripheral blood lymphocytes or pokeweed mitogen blasts. They possess the sheep red blood cell receptor but lack other T cell markers (Lyt-3+, OKT3-). Natural killer activity correlated with the presence of a Mac 1-positive subpopulation of cells present in these long-term lines.