Phosphonic acid derivatives of 1,3-dioxan: Potential plant growth regulators

A series of novel (0,0-dialkyl)phosphono derivatives of 1,3-dioxan was prepared, with various alkyl substituents on different positions on the ring carbon atoms. The compounds were obtained by an Arbuzov-type rearrangement of trialkyl phosphites either with halogenoacetals or with 2-alkoxy-1,3-dioxans. The products were tested as potential plant growth regulators, using as a primary screen the effect in a tissue culture of green and white cells, followed by algal growth experiments, green-house tests on barley and maize, and small scale field trials on cucumber, tomato and maize.     

Metabolic programs define dysfunctional immune responses in severe COVID-19 patients

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Nerve Growth Factor Mediates Monosialoganglioside-Induced Release of Fibronectin and J1/Tenascin from C6 Glioma Cells

C6 rat glioma cells incubated in serum-free medium with D-[14C]glucosamine secrete, on stimulation with nerve growth factor (NGF) or monosialogangliosides (MSGs), several glycoproteins (Gps), the most prominent of which are a 270-, 220-, and 69-kDa Gp. Several growth factors, hormones, phorbol ester, and disialo- and trisialogangliosides did not stimulate secretion. Western blot analysis of the conditioned medium from C6 cells stimulated with NGF or MSG identified one distinct band of approximately 220 kDa for fibronectin and J1/tenascin, which comigrated. Antiserum to NGF prevented NGF-stimulated release and also blocked MSG-evoked release. The 220-kDa band was labeled after pulse labeling with [35S]methionine in the presence of NGF, and by a 15-min chase period radioactively labeled J1/tenascin could be immunoprecipitated. Tunicamycin drastically inhibited almost completely release of the 220-kDa Gp labeled by D-[14C]glucosamine or [35S]methionine. These results extend the range of neurotrophic properties attributed to NGF to cells of glial origin and suggest that NGF regulates secretion of extracellular matrix proteins. MSG stimulation of fibronectin and J1/tenascin secretion may be mediated by NGF or an NGF-like molecule also secreted by the C6 glioma cells.