A method is described for determining total oxalates in plants, by extraction with hydrochloric acid, precipitation as calcium oxalate from the deproteinised extract and subsequent titration with potassium permanganate. Soluble oxalates are determined in a similar manner, in aqueous extract. The later stages of the determination are carried out on a semi-micro scale, so that a number of determinations can be made simultaneously. The method is designed for fresh green plants only, as oxalate is lost on drying the material.

1. Studies were made of the composition of Giant sainfoin cut successively at different stages of growth in two seasons under contrasting conditions of weather and soil.2. Cuts were taken at preflowering, early- and full-flowering stages of growth. Yields of both fresh material and dry matter substantiated the usual farming practice of taking two cuts at full flower in one season, and indicate that cutting sainfoin before it comes into bloom has a seriously depressing effect on productivity.3. Like most green fodder crops, sainfoin has a lower content of crude protein and nitrogen-free extractives, and a higher content of crude fibre as the plant increases in maturity. The mineral content is somewhat variable, and in particular the potassium content appears to reflect the status of this element in the soil.4. The ratio of leaf dry matter to total dry matter of the plant decreases with advancing maturity. The leaf composition is fairly constant, irrespective of stage of growth, number of cuts and season, the fibre content being remarkably constant in contrast with that of stem, where it increases with advancing maturity. Leaf is richer than stem in crude protein, ether extract and total mineral matter, particularly calcium. Thus changes which do occur in the composition of the plant are due to variations in stem composition and leaf-stem ratio.5. Analyses of sainfoin hay, made under both experimental and commercial conditions, are discussed, and the range of variation in the main constituents of thirty-five commercial samples is commented upon.6. The present investigations into the composition of sainfoin, both as green fodder and as hay, show figures that differ appreciably from those derived from earlier German work. Examination of the data available for the nutritive value of fresh and conserved sainfoin reveal anomalies which suggest that such data are not typical of the crop as grown in this country, and also suggest the need for more modern data.

1. Studies were made during the 1951 and 1952 seasons of the oxalate contents of the leaves of mangolds, sugar mangolds and fodder sugar beet.2. In all varieties greater concentrations of total oxalates were found during the summer months, the amounts diminishing gradually as the season advanced. Up to 12% was found in the dry-matter of mangold leaves and 9% in fodder sugar-beet leaves in July, these levels falling to 3% by mid-winter. There is some evidence that these changes are due in part to loss of outer leaves.3. Roughly one-third of the oxalates are present in water-soluble form. The addition of 1 part of chalk to 1000 parts of leaves, as has been generally recommended, is theoretically sufficient to render unavailable the soluble oxalates present during winter, but insufficient for leaves fed earlier hi the season.4. A number of observations showed small reductions in the soluble oxalate contents of the leaves due to wilting, but there were exceptions to this, and these appear to be related to sampling periods rather than to varieties.5. Insoluble oxalates appear to be unaffected by wilting and may show apparent increases in amount due to respiration losses of labile leaf constituents. The insoluble/soluble oxalate ratio is thus changed by wilting.6. It is suggested that the undesirable effects sometimes resulting from the feeding of beet leaves to livestock may not be due to oxalates, but that other factors present, which are labile during wilting, may be involved.

OBJECTIVE The Rare and Atypical Diabetes Network (RADIANT) will perform a study of individuals and, if deemed informative, a study of their family members with uncharacterized forms of diabetes. RESEARCH DESIGN AND METHODS The protocol includes genomic (whole-genome [WGS], RNA, and mitochondrial sequencing), phenotypic (vital signs, biometric measurements, questionnaires, and photography), metabolomics, and metabolic assessments. RESULTS Among 122 with WGS results of 878 enrolled individuals, a likely pathogenic variant in a known diabetes monogenic gene was found in 3 (2.5%), and six new monogenic variants have been identified in the SMAD5, PTPMT1, INS, NFKB1, IGF1R, and PAX6 genes. Frequent phenotypic clusters are lean type 2 diabetes, autoantibody-negative and insulin-deficient diabetes, lipodystrophic diabetes, and new forms of possible monogenic or oligogenic diabetes. CONCLUSIONS The analyses will lead to improved means of atypical diabetes identification. Genetic sequencing can identify new variants, and metabolomics and transcriptomics analysis can identify novel mechanisms and biomarkers for atypical disease.

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