BioAssay Research Database (BARD): chemical biology and probe-development enabled by structured metadata and result types.

BARD, the BioAssay Research Database (https://bard.nih.gov/) is a public database and suite of tools developed to provide access to bioassay data produced by the NIH Molecular Libraries Program (MLP). Data from 631 MLP projects were migrated to a new structured vocabulary designed to capture bioassay data in a formalized manner, with particular emphasis placed on the description of assay protocols. New data can be submitted to BARD with a user-friendly set of tools that assist in the creation of appropriately formatted datasets and assay definitions. Data published through the BARD application program interface (API) can be accessed by researchers using web-based query tools or a desktop client. Third-party developers wishing to create new tools can use the API to produce stand-alone tools or new plug-ins that can be integrated into BARD. The entire BARD suite of tools therefore supports three classes of researcher: those who wish to publish data, those who wish to mine data for testable hypotheses, and those in the developer community who wish to build tools that leverage this carefully curated chemical biology resource.

Exploiting site-site interactions on solid support to generate dimeric molecules.

[structure: see text]. "Intra-site" olefin cross-metathesis on solid support leads to nearly quantitative yields of dimeric molecules.

A one-bead, one-stock solution approach to chemical genetics: part 2.

BACKGROUND: Chemical genetics provides a systematic means to study biology using small molecules to effect spatial and temporal control over protein function. As complementary approaches, phenotypic and proteomic screens of structurally diverse and complex small molecules may yield not only interesting individual probes of biological function, but also global information about small molecule collections and the interactions of their members with biological systems. RESULTS: We report a general high-throughput method for converting high-capacity beads into arrayed stock solutions amenable to both phenotypic and proteomic assays. Polystyrene beads from diversity-oriented syntheses were arrayed individually into wells. Bound compounds were cleaved, eluted, and resuspended to generate 'mother plates' of stock solutions. The second phase of development of our technology platform includes optimized cleavage and elution conditions, a novel bead arraying method, and robotic distribution of stock solutions of small molecules into 'daughter plates' for direct use in chemical genetic assays. This library formatting strategy enables what we refer to as annotation screening, in which every member of a library is annotated with biological assay data. This phase was validated by arraying and screening 708 members of an encoded 4320-member library of structurally diverse and complex dihydropyrancarboxamides. CONCLUSIONS: Our 'one-bead, multiple-stock solution' library formatting strategy is a central element of a technology platform aimed at advancing chemical genetics. Annotation screening provides a means for biology to inform chemistry, complementary to the way that chemistry can inform biology in conventional ('investigator-initiated') small molecule screens.

How do the results of the diabetes control and complications trial relate to the practice of pediatrics: who should have intensive management?

The DCCT showed that any improvement in glycemic control decreases the risk of long-term complications. Although expensive, time consuming, and associated with increased risks of hypoglycemia and obesity, improved glycemic control is of benefit as long as hypoglycemia is avoided. Specific HbA1c target levels must be individualized and age appropriate.

Inductively coupled plasma mass spectrometry with an enlarged sampling orifice and offset Ion Lens. I. Ion trajectories and detector performance.

A new inductively coupled plasma mass spectrometer (ICP-MS) with four stages of differential pumping is described. The relatively large sampling orifice (1.31-mm dia.) improves signals for metal ions and resists plugging from deposited solids. A new ion lens is described that deflects ions off center and then back on center into the differential pumping orifice; there is no photon stop in the center of the beam. Calculations of ion trajectories using SIMIOn show that only those ions that leave the skimmer on center are transmitted, whereas most other lenses used in ICP-MS transmit only ions that leave the skimmer off axis. The performance of a Channeltron electron multiplier is compared to that of a Daly detector. Both detectors yield similar sensitivities of ≈ 10(6) counts s(-1) per ppm and detection limits of ≈ 1 pptr. The background with a Channeltron electron multiplier is only 0.4 counts s(-1) and is only slightly higher than the dark current count rate. Presumably the offset ion lens used in the present work efficiently screens the detector from photons emitted by the plasma. The background with the Daly detector is 4 counts s(-1), which represents a substantial improvement over the background obtained in previous use of the Daly detector with JCP-MS.

Insulin autoantibodies at diagnosis of insulin-dependent diabetes: effect on the antibody response to insulin treatment.

Insulin autoantibodies (IAA) are frequently found in newly diagnosed untreated insulin-dependent diabetics. We evaluated whether the insulin antibody response over the first year of treatment with insulin was different in individuals with IAA v those without IAA. One hundred five previously untreated type I diabetics were randomly assigned to treatment with either pure porcine or mixed bovine/porcine insulin. Twenty-one in each group had detectable IAA at diagnosis. Percent binding rose in all patients after commencing insulin therapy and was significantly greater in those with IAA at diagnosis irrespective of the type of insulin administered. The elevated binding in the IAA positive patients at all time points was equivalent to the binding that could be attributed to the insulin autoantibodies. Two different mechanisms could explain this greater insulin antibody binding during insulin therapy in the IAA positive patients. First, there may be summation of binding due to insulin autoantibodies and binding due to insulin antibodies formed in response to the exogenous insulin. Alternatively, the insulin antibodies formed in response to exogenous insulin could replace the IAA, with those individuals positive for IAA at diagnosis having a proportionately greater antibody response to injected insulin. Irrespective of the mechanism, patients with IAA at diagnosis develop higher insulin antibody measurements when subsequently treated with exogenous insulin.

Randomized prospective trial of pure porcine and conventional bovine/porcine insulin.

Use of pure porcine insulin versus partially purified insulin of bovine/porcine origin might be expected to have certain clinical benefits, e.g., a lower incidence of skin reactions, a lower insulin dosage, better diabetes regulation, and greater preservation of endogenous insulin secretion. To test this hypothesis, we randomly assigned 112 newly diagnosed, untreated, insulin-dependent diabetic children to therapy with either pure porcine or partially purified bovine/porcine insulin. They were followed for 1 yr, data being available on at least 90 subjects at each visit. More skin reactions were found in the group treated with the bovine/porcine insulin. This insulin was of higher antigenicity, and binding of radiolabeled insulin (mean +/- SE) by serum from bovine/porcine insulin treatment was 35.5 +/- 2.6 versus 16.8 +/- 1.4% (P less than .001) for pure porcine insulin treatment 12 mo after initiation of insulin therapy. However, throughout the 12 mo of observation the levels of glycosylated hemoglobin, insulin dosage, fasting plasma glucose, and C-peptide concentration were similar for the groups. Reported incidences of hypoglycemia and nocturia were also similar. Thus, insulin-antibody formation and skin reactions were minimized by the use of pure porcine versus partially purified bovine/porcine insulin, but no other clinical advantages were apparent.

Puberty decreases insulin sensitivity.

Puberty is commonly associated with an increase in insulin requirement in patients with insulin-dependent diabetes. To investigate whether this pubertal increase in insulin requirement is confined to diabetic subjects, we examined insulin responses during oral glucose tolerance testing with glucose loads per unit weight (1.75 g/kg) or unit surface area (55 g/m2), and insulin sensitivity via euglycemic-hyperinsulinemic clamp in prepubertal and pubertal children without diabetes. Irrespective of glucose dose, glucose tolerance testing elicited a threefold greater insulin response, but equivalent euglycemia, in pubertal versus prepubertal children (P less than 0.05). As assessed by the clamp procedure, prepubertal children were approximately 30% more sensitive than their pubertal counterparts (P less than 0.01). Insulin sensitivity correlated inversely with body mass index (r = -0.49, P less than 0.02), serum dehydroepiandrosterone sulphate concentration (r = -0.57, P less than 0.01), and log somatomedin C/insulinlike growth factor I (r = -0.45, P less than 0.05). We conclude that puberty is associated with decreased sensitivity to insulin that normally is compensated for by increased insulin secretion. Thus, in patients with insulin-dependent diabetes, an approximately 30% increase in insulin dosage should be anticipated with the onset of puberty.

Insulin antibodies in insulin-dependent diabetics before insulin treatment.

A sensitive assay was used to measure the binding of iodine-125-labeled insulin in serum obtained from 112 newly diagnosed insulin-dependent diabetics before insulin treatment was initiated. Two groups of nondiabetics served as controls: children with a variety of diseases other than diabetes and nondiabetic siblings of insulin-dependent diabetics. Eighteen of the diabetics were found to have elevated binding and 36 were above the 95th percentile of control values. The insulin-binding protein is precipitated by antibody to human immunoglobulin G, has a displacement curve that is parallel and over the same concentration range as serum from long-standing insulin-dependent diabetics, and elutes from a Sephacryl S-300 column at the position of gamma globulin. These insulin antibodies are present in a large percentage of newly diagnosed, untreated diabetics and may be an immune marker of B-cell damage.