A new view on an old drug: Pilocarpine

Zusammenfassung Pilocarpin ist ein geeignetes Beispiel einer parasympathischen Substanz mit dualistischer Wirkung. Auf Grund der Variationen in der Eigenaktivität (intrinsic activity) des Pilocarpins an verschiedenen Organen und Arten tritt entweder die parasympathomimetische oder die parasympatholytische Wirkung in den Vordergrund.     

On the biogenesis of neoflavanoids: A new hypothesis

Zusammenfassung Eine neue Hypothese für die Biogenese der Neoflavanoide wird vorgeschlagen, indem dasselbe Chalkon als Zwischenstufe wie für die Flavanoide postuliert wird. Nach dieser Hypothese sollte sich nach Verabreichung von [3-¹⁴C]-Phenylalanin die Markierung an C-4 des Neoflavanoids befinden, wie es beim Calophyllolid⁶ tatsächlich der Fall ist.     

Role of serotonin in the hepato-gastroIntestinal tract: an old molecule for new perspectives

Beside its role as a neurotransmitter in the central nervous system, serotonin appears to be a central physiologic mediator of many gastrointestinal (GI) functions and a mediator of the brain-gut connection. By acting directly and via modulation of the enteric nervous system, serotonin has numerous effects on the GI tract. The main gut disturbances in which serotonin is involved are acute chemotherapy-induced nausea and vomiting, carcinoid syndrome and irritable bowel syndrome. Serotonin also has mitogenic properties. Platelet-derived serotonin is involved in liver regeneration after partial hepatectomy. In diseased liver, serotonin may play a crucial role in the progression of hepatic fibrosis and the pathogenesis of steatohepatitis. Better understanding of the role of the serotonin receptor subtypes and serotonin mechanisms of action in the liver and gut may open new therapeutic strategies in hepato-gastrointestinal diseases. Received 15 August 2007; received after revision 1 November 2007; accepted 5 November 2007     

Possible involvement of the phloem sealing system in the acceptance of a plant as host by an aphid

Possible reasons for the rejection of some lines ofTriticum monococcum (Tm44 and Tm46) by the aphidSitobion avenae were explored. In allT. monococcum lines studied, whether unfavourable (non-host/resistant plant) or favourable (host/susceptible plant), the concentrations of hydroxamic acids, a family of aphid-resistance factors in cereals, were significantly lower than the levels in the favourable host-plantTriticum aestivum cv. Therefore, hydroxamic acids did not account for the host/non-host patterns observed. Phloem sap was collected by stylectomy from young seedlings of favourable and unfavourable plants. In non-aphid-resistant genotypes, the success in stylectomy, the proportion of amputated stylets resulting in long (>1 min) exudations, the average duration of exudation, and the final volume of sap exuded, were higher than in the aphid-resistant genotypes. It is concluded that aphid interference with the phloem sealing system of the plant is a likely mechanism of rejection ofT. monococcum lines Tm44 and Tm46 as hosts byS. avenae.     

From old organisms to new molecules: integrative biology and therapeutic targets in accelerated human ageing

Understanding the basic biology of human ageing is a key milestone in attempting to ameliorate the deleterious consequences of old age. This is an urgent research priority given the global demographic shift towards an ageing population. Although some molecular pathways that have been proposed to contribute to ageing have been discovered using classical biochemistry and genetics, the complex, polygenic and stochastic nature of ageing is such that the process as a whole is not immediately amenable to biochemical analysis. Thus, attempts have been made to elucidate the causes of monogenic progeroid disorders that recapitulate some, if not all, features of normal ageing in the hope that this may contribute to our understanding of normal human ageing. Two canonical progeroid disorders are Werner's syndrome and Hutchinson-Gilford progeroid syndrome (also known as progeria). Because such disorders are essentially phenocopies of ageing, rather than ageing itself, advances made in understanding their pathogenesis must always be contextualised within theories proposed to help explain how the normal process operates. One such possible ageing mechanism is described by the cell senescence hypothesis of ageing. Here, we discuss this hypothesis and demonstrate that it provides a plausible explanation for many of the ageing phenotypes seen in Werner's syndrome and Hutchinson-Gilford progeriod syndrome. The recent exciting advances made in potential therapies for these two syndromes are also reviewed.     

HLA groups in the infantile psychoses during development, and hypothesis for an enzyme defect]

The HLA typing (loci A and B) of a series of fifteen psychotic children has shown an increase of the frequency of both HLA-A9 and B5 antigens. These preliminary data and previous biochemical findings in psychotic patients lead the authors to postulate the hypothesis of a qualitative or quantitative anomaly of the superoxide dismutase (SOD-2), the gene of which is situated on the same chromosome (sixth) as the HLA complex.     

A new class of cytostatic folic acid antagonists 1-(3,4-Dichlorophenyl)-5-isopropyl-biguanide and its boron compounds

Zusammenfassung 1-(3,4-Dichlorphenyl)-5-isopropyl-biguanid (I) besitzt cytostatische Eigenschaften, die speziesabhängig sind. I übt eine stark depressive Wirkung auf die Hämatopoese von Meerschweinchen, Katze und Mensch aus, während das Knochenmark von Maus, Ratte, Kaninchen und Hund nicht beeinflusst wird. Transplantable Tumoren von Maus und Ratte werden in ihrem Wachstum nicht gehemmt. Hingegen liessen sich beim Menschen objektive Regressionen einiger Tumorarten beobachten. Die Wirkung auf die Meerschweinchenleukopenie kann durch Formyltetrahydrofolsäure aufgehoben werden. I hemmt die Dihydrofolatreduktase der auf I empfindlichen Spezies Meerschweinchen, nicht aber das entsprechende Ferment der auf I resistenten Spezies Ratte. Der Folsäureantagonismus ist speziesabhängig, was auf eine verschiedene Empfindlichkeit der Dihydrofolatreduktasen und nicht auf einen verschiedenen Metabolismus zurückzuführen sein dürfte. Borverbindungen von I besitzen ähnliche cytostatische Eigenschaften.     

A new solution of the equilibrium equation for an isothermal gas sphere

Zusammenfassung Eine neue Lösung der Gleichgewichtsgleichung in der (, )-Ebene wurde für eine isotherme Gaskugel gefunden.     

Ptolemy's maps of earth and the heavens: A new interpretation

Communicated by A. Aaboe     

A new liver-specific autoantigen in the rat: Delta antigen

Zusammenfassung Es werden einige Eigenschaften eines leberspezifischen Antigensystems der Ratte beschrieben. Es wird gezeigt, dass das entsprechende Antigen aus Lewis-Ratten in BN-Ratten einen universell kreuzreagierenden Autoantikörper induziert.     

A new type of ‘node’ in the myelin sheath of an invertebrate nerve fibre

Zusammenfassung Es werden neuartige, segmental angeordnete Öffnungen in der Myelinscheide der medianen Riesenfaser des RegenwurmsLumbricus terrestris beschrieben, durch welche die Axonmembran direkt an die extrazelluläre Kollagenhülle des Bauchmarkperineuriums heranreicht. Dieser Befund wird in Hinblick auf den Mechanismus der Erregungsleitung myelinisierter Nervenfasern von Wirbellosen diskutiert.

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This work was suported in part by a DFG Grant No. Gu/117/1. The technical assistance of Mrs.H. Eggert is thankfully acknowledged.