Phosphates would probably have been essential compounds for prebiotic evolution on the primitive Earth. In this context, there have been several studies of condensation of water-soluble phosphates to polyphosphates and phosphorylation and condensation or polymerization of biomolecules with polyphosphates. But most of the phosphorus on the early Earth would have been in the form of water-insoluble apatite, and the origin of the water-soluble polyphosphates required for prebiotic evolution has therefore been a mystery. Here we show, both from experiments that simulate magmatic conditions and from analysis of volatile condensates in volcanic gas, that volcanic activity can produce water-soluble polyphosphates through partial hydrolysis of P4O10. This mechanism seems to be the only viable route identified so far for the production of these species on the primitive Earth.

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Aim: To elucidate prognosis and prevalence of chronic renal diseases among proteinuric and/or hematuric subjects found in mass screening, a long-term follow-up study (6.35 years, range 1.03–14.6 years) was conducted on Japanese working men. Methods: A total of 772 subjects selected from 50,501 Japanese men aged 15–62 years were found to have asymptomatic hematuria (n = 404), concomitant hematuria and proteinuria (n = 155), and proteinuria (n = 213) during their annual urine examination and five consecutive urinalyses. Results: Hematuria patients showed significant improvements in urinary abnormalities as compared with both hematuria/proteinuria and proteinuria patients. Both hematuria/proteinuria patients with normotension and hematuria/proteinuria patients aged under 40 years showed significant improvements. During the follow-up period, 9.5% of the hematuria patients became hematuric/proteinuric. Hematuria/proteinuria patients had the highest risk of developing renal insufficiency. The presence of hypertension at detection of urinary abnormalities did not affect the renal function; however, if proteinuria appeared after the age of 40 years, these patients had a higher risk of developing renal insufficiency. The incidence of IgA nephropathy in the present subjects was as high as 143 cases per 1 million per year. Conclusion: Detailed follow-up and definitive diagnosis of asymptomatic urinary abnormalities may raise the prevalence of IgA nephropathy worldwide.

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The dehydration condensation of glycine with trimetaphosphate in aqueous solution has been reinvestigated. Although it has been reported that the condensation of glycine under the alkaline conditions was brought about through the formation of cyclic acylphosphoramidate and hence the condensation of polyglycines could not occur, we found that the condensation of oligoglycines with trimeta- and tetrametaphosphate in aqueous solution are possible through the formation of their acylphosphates under the neutral or weak acidic conditions. Aqueous solutions of 1.0 M glycylglycine and 1.0 M trimetaphosphate in the various pH from 4.0 to 9.0 were incubated at 38 degrees C. The solutions were analyzed by HPLC with ninhydrin reaction system. Tetraglycine and hexaglycine were detected and their maximum yields were given in the reaction carried out around pH 7. They are approximately 15% and 4% after 30 days, respectively. Analogous experiments were performed with tetrametaphosphate. The results showed a similar pH dependence for the condensation, but the yields were about one-tenth of those of corresponding experiments with trimetaphosphate. Relative rates of dimerization of glycine, diglycine and triglycine in the equimolar concentration were also investigated at pH 6.0 at 38 degrees C. The rates for diglycine and triglycine were approximately twice and four times as large as that for glycine. Relevance of the experiments to chemical evolution is discussed.