A new quaternary ammonium compound with plant growth regulatory activity

Summary Of several quaternary ammonium derivatives tested, 1-allyl-1-(3,7-dimethyloctyl)piperidinium bromide showed the best growth-retarding activity. OnChrysanthemum morifolium the growth retardation obtained with a single application of 100–200 ppm compared favourably with that obtained from 2–3 applications of 3400 ppm of N-dimethylaminosuccinamic acid (daminozide).     

Regulation of calcium signalling in T lymphocytes by the second messenger cyclic ADP-ribose

Cyclic ADP-ribose (cADPR) is a natural compound that mobilizes calcium ions in several eukaryotic cells. Although it can lead to the release of calcium ions in T lymphocytes, it has not been firmly established as a second messenger in these cells. Here, using high-performance liquid chromatography analysis, we show that stimulation of the T-cell receptor/CD3 (TCR/CD3) complex results in activation of a soluble ADP-ribosyl cyclase and a sustained increase in intracellular levels of cADPR. There is a causal relation between increased cADPR concentrations, sustained calcium signalling and activation of T cells, as shown by inhibition of TCR/CD3-stimulated calcium signalling, cell proliferation and expression of the early- and late-activation markers CD25 and HLA-DR by using cADPR antagonists. The molecular target for cADPR, the type-3 ryanodine receptor/calcium channel, is expressed in T cells. Increased cADPR significantly and specifically stimulates the apparent association of [3H]ryanodine with the type-3 ryanodine receptor, indicating a direct modulatory effect of cADPR on channel opening. Thus we show the presence, causal relation and biological significance of the major constituents of the cADPR/calcium-signalling pathway in human T cells.     

Occurrence of a new type of mosaicism inApis mellifera

Summary A mixture of tissue with male and female olfactory plates (sensilla placodea) was observed in the antennal segments number 8, 9 and 10 of a gynandromorphic honeybee obtained by radiation from a Co⁶⁰ source.Work carried out with financial help of Fundação de Amparo A Pesquisa do Estado de São Paulo, Brazil.     

Potentiation of bradykinin and eledoisin by BPF (bradykinin potentiating factor) fromBothrops jararaca venom

Zusammenfassung Nachweis der pharmakologischen Wirkung des Bradykinins am isolierten Meerschweinchenileum und am deutlichen Blutdruckanstieg bei Hund und Katze nach Vorbehandlung mit BPF (Bradykinin-potenzierender Faktor aus Jararcagift). Unter diesen Bedingungen werden mit Bradykinin gleich intensive Effekte wie mit Eldoisin erhalten.

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This work was aided by research grants from the Fundação de Amparo à Pesquisa and from the Public Health Service, National Institute of Health, Bethesda (Md. USA) (NB. 02953-03).     

A physical map of human chromosome 14

We report the construction of a tiling path of around 650 clones covering more than 99% of human chromosome 14. Clone overlap information to assemble the map was derived by comparing fully sequenced clones with a database of clone end sequences (sequence tag connector strategy). We selected homogeneously distributed seed points using an auxiliary high-resolution radiation hybrid map comprising 1,895 distinct positions. The high long-range continuity and low redundancy of the tiling path indicates that the sequence tag connector approach compares favourably with alternative mapping strategies.