Search for Invisible Axion Dark Matter with the Axion Dark Matter Experiment.

This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 µeV. The search excludes the range of axion-photon couplings predicted by plausible models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume haloscope at subkelvin temperatures, thereby reducing thermal noise as well as the excess noise from the ultralow-noise superconducting quantum interference device amplifier used for the signal power readout. Ongoing searches will provide nearly definitive tests of the invisible axion model over a wide range of axion masses.

Piezoelectrically Tuned Multimode Cavity Search for Axion Dark Matter.

The µeV axion is a well-motivated extension to the standard model. The Axion Dark Matter eXperiment (ADMX) collaboration seeks to discover this particle by looking for the resonant conversion of dark-matter axions to microwave photons in a strong magnetic field. In this Letter, we report results from a pathfinder experiment, the ADMX "Sidecar," which is designed to pave the way for future, higher mass, searches. This testbed experiment lives inside of and operates in tandem with the main ADMX experiment. The Sidecar experiment excludes masses in three widely spaced frequency ranges (4202-4249, 5086-5799, and 7173-7203 MHz). In addition, Sidecar demonstrates the successful use of a piezoelectric actuator for cavity tuning. Finally, this publication is the first to report data measured using both the TM_{010} and TM_{020} modes.

aCORN: An experiment to measure the electron-antineutrino correlation coefficient in free neutron decay.

We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects.

The aCORN Backscatter-Suppressed Beta Spectrometer.

Backscatter of electrons from a beta spectrometer, with incomplete energy deposition, can lead to undesirable effects in many types of experiments. We present and discuss the design and operation of a backscatter-suppressed beta spectrometer that was developed as part of a program to measure the electronantineutrino correlation coefficient in neutron beta decay (aCORN). An array of backscatter veto detectors surrounds a plastic scintillator beta energy detector. The spectrometer contains an axial magnetic field gradient, so electrons are efficiently admitted but have a low probability for escaping back through the entrance after backscattering. The design, construction, calibration, and performance of the spectrometer are discussed.

Cavity design for high-frequency axion dark matter detectors.

In an effort to extend the usefulness of microwave cavity detectors to higher axion masses, above ∼8 µeV (∼2 GHz), a numerical trade study of cavities was conducted to investigate the merit of using variable periodic post arrays and regulating vane designs for higher-frequency searches. The results show that both designs could be used to develop resonant cavities for high-mass axion searches. Multiple configurations of both methods obtained the scanning sensitivity equivalent to approximately 4 coherently coupled cavities with a single tuning rod.

Anti-rheumatic gold compounds as sublethal modulators of monocytic LPS-induced cytokine secretion.

The objective of this study was to quantify the ability of sublethal concentrations of several gold compounds to differentially modulate the monocytic secretion of key cytokines that are important in the etiology of rheumatic diseases. Human THP1 monocytic cells were exposed to the anti-rheumatic drugs auranofin (AF), gold sodium thiomalate (GSTM) or HAuCl4 (Au(III)) for 24-72 h. Succinate dehydrogenase (SDH) activity of the monocytes was used to determine sublethal concentrations. Monocytes were then exposed to sublethal concentrations of gold compounds for 72 h, and the activator lipopolysaccharide (LPS) was added (or not) to cultures for the last 6h. The secretion of IL6, IL8, IL10, and TNFalpha were measured in cell supernatants using ELISA. Cytokine secretion was compared among concentrations and gold compounds. SDH experiments established a sublethal concentration range of 0-75 microM for GSTM and Au(III) and 0-0.5 microM for AF. In cytokine experiments, none of the compounds alone activated secretion of any of the cytokines, but all differentially (50-440%, p<0.05) increased LPS-induced secretion of IL6 and IL8 over TNFalpha and IL10. In conclusion, sublethal concentrations of AF, GSTM, and Au(III) all may differentially modulate activation of monocytic cells, and this differential modulation may be important in the mechanisms of action of these compounds.

Structure of human dipeptidyl peptidase I (cathepsin C): exclusion domain added to an endopeptidase framework creates the machine for activation of granular serine proteases.

Dipeptidyl peptidase I (DPPI) or cathepsin C is the physiological activator of groups of serine proteases from immune and inflammatory cells vital for defense of an organism. The structure presented shows how an additional domain transforms the framework of a papain-like endopeptidase into a robust oligomeric protease-processing enzyme. The tetrahedral arrangement of the active sites exposed to solvent allows approach of proteins in their native state; the massive body of the exclusion domain fastened within the tetrahedral framework excludes approach of a polypeptide chain apart from its termini; and the carboxylic group of Asp1 positions the N-terminal amino group of the substrate. Based on a structural comparison and interactions within the active site cleft, it is suggested that the exclusion domain originates from a metallo-protease inhibitor. The location of missense mutations, characterized in people suffering from Haim-Munk and Papillon-Lefevre syndromes, suggests how they disrupt the fold and function of the enzyme.

[Fiber-enriched cereal for constipation and for hypercholesterolemia].

A mixed-grain, high-fiber cereal (Disivit) prepared from oats, corn, wheat and soybean was used to treat 20 patients with chronic constipation and 22 with hypercholesterolemia in double-blind, cross-over trials. Disivit (50 g/d, containing 12.5 g dietary fiber) was given to the constipated patients for 2 weeks and then a low-fiber placebo for another 2 weeks, and similarly for the hypercholesterolemic patients. In those with constipation, the frequency of bowel movements increased significantly, stools became softer and laxative intake decreased. In hypercholesterolemic patients serum cholesterol decreased significantly, but only by 15%. Thus the fiber cereal appears to be a suitable treatment for constipation, while for hypercholesterolemia a larger dose or a longer period of treatment may be required.

Structure and chromosomal localization of human insulin-like growth factor-binding protein genes.

The insulin-like growth factor binding proteins (IGFBPs) constitute a structurally related protein family with six known members. We have mapped and regionally localized the genes coding for human IGFBP1, 2, 3, and 4, by in situ hybridization and somatic cell hybrid analysis. The IGFBP2 gene maps to chromosomal region 2q33-q34 whereas the genes for IGFBP1 and 3 are localized in a tail-to-tail fashion on chromosome 7 region p14-p12. The IGFBP4 gene is located in the chromosomal region 17q12-21.1. Structural characterization of the genes coding for IGFBP-1, 2, 3, and 5 showed that the translated parts are divided into four exons. The exons are similar both in size and sequence in all studied genes.

Insulin-like growth factor binding protein-1 from Hep G2 cells is potently inhibited by the truncated IGF-I analogue des-(1-3) IGF-I.

Des-(1-3) insulin-like growth factor-I (IGF-I) is an IGF analogue lacking aminoacid 1 to 3 which displays reduced binding to insulin-like growth factor binding protein-1 (IGFBP-1). A greater inhibition of immunoreactive IGFBP-1 was obtained with des-(1-3) IGF-I (10 ng/ml) in Hep G2 medium when incubated in Eagle's Modified Essential Medium (EMEM) without phenolred compared to EMEM with phenolred; EMEM without phenolred was chosen for further experiments. Des-(1-3)IGF-I decreases dose dependently the concentration of IGFBP-1, with a maximal effect at 3-10 micrograms/l when incubated for 24 h; 10 micrograms/l of des-(1-3)IGF-I caused a small but significant inhibition of IGFBP-1 after 8 h incubation and this inhibition was 41% and 33% of controls after 14 and 19 h incubation. The relative potencies at 16 h of incubation of IGF-I and insulin in suppressing IGFBP-1 in comparison to des-(1-3)IGF-I were 0.41 (0.25-0.78) and 0.08 (0.01-0.26), respectively. A dose-dependent decrease of IGFBP-1 mRNA to 30% of control was observed after 4 h incubation with 0.1-10 micrograms/l des-(1-3)IGF-I. Changes of glucose concentration (0-20 mmol/l) in the medium did not affect the IGFBP-1 concentration in the medium. In summary: Des-(1-3)IGF-I was tenfold more potent than insulin, and threefold more potent than IGF-I in decreasing IGFBP-1 concentration in medium conditioned by Hep G2 cells.

Spatial distribution of active genes implicated in the regulation of insulin-like growth factor stimulatory loops in human decidual and placental tissue of first-trimester pregnancy.

We have previously shown that the insulin-like growth factor-2 (IGF-2) gene is partially coexpressed with the IGF-1 and -2 receptor genes in proliferative cytotrophoblasts of the human extraembryonic tissue. Here we show that high levels of IGF-2 gene expression are not restricted to the embryonic tissue but can also be found in the decidua compacta. The IGF-2 gene is thus expressed at high levels in the mesenchymal stroma of the decidua to establish potentially short-range communication with primarily IGF-1 receptor-positive mesenchymal stroma cells. Conversely, the glandular and surface epithelia coexpress the IGF-1 receptor and IGF-1 genes, while the IGF-2 gene is not detected above background levels. The potential control mechanisms of these cell-cell signalling pathways were investigated by the analysis of the spatial distribution of active IGF binding proteins (IGFBP) genes. The IGFBP-3 gene is coexpressed with the IGF-2 gene in proliferative cytotrophoblasts of the embryonic placenta. While active IGFBP-1 and -2 genes in our hands cannot be detected in the embryonic placenta, all three IGFBP genes are expressed in complex and overlapping patterns in the decidua compacta. The results are discussed in terms of how the various IGFBP genes may operate in different cell types to restrict IGF local stimulatory pathways.

Contiguous localization of the genes encoding human insulin-like growth factor binding proteins 1 (IGBP1) and 3 (IGBP3) on chromosome 7.

In extracellular fluids the insulin-like growth factors (IGFs) are bound to specific binding proteins (IGBPs). The genes for two members of this protein family have been mapped, the IGBP1 gene to human chromosomal region 7p14-p12 and the IGBP2 gene to region 2q33-q34. In this study, somatic cell hybrid analysis indicated that IGBP3 is also located on chromosome 7. Pulsed-field gel electrophoresis was used to demonstrate the close physical linkage between IGBP1 and IGBP3. Overlapping cosmid clones encompassing these genes were isolated, and restriction endonuclease mapping showed that the genes are arranged in a tail-to-tail fashion separated by 20 kb of DNA. Further characterization of the IGBP1 DNA sequence disclosed a duplication of the intron 3-exon 4 junction within the third intron. In addition, we report RFLPs for ApaLI and TaqI in the IGBP1 locus.

Structure and localization of the human insulin-like growth factor-binding protein 2 gene.

Insulin-like growth factor binding proteins (IGFBPs) are extracellular proteins that specifically bind IGF and modulate their effects. The human IGFBP2 gene was studied and shown to be localized to chromosome 2 region q33-q34, by somatic cell hybrid analysis and in situ hybridization. Structural characterization of the gene showed that it consists of four exons with three introns of lengths 27.0, 1.0, and 1.9 kilobase-pairs. Comparison of the encoded protein sequence of each exon in IGFBP1, 2, and 3 reveals the highest amino acid identity, 28%, in exon 1, while the lowest was found in exon 2. However, pairwise sequence comparisons demonstrate 50% identity between the protein sequences encoded by exon 4 in IGFBP1 and 2, while their respective identities with IGFBP3 are only 25 and 30%.

Screening for insulin receptor gene DNA polymorphisms associated with glucose intolerance in a Scandinavian population.

The significance of insulin receptor gene variants in the aetiology of Type 2 (non-insulin-dependent) diabetes mellitus has been investigated by analysis of restriction fragment length polymorphisms in a genetically homogeneous Swedish population. Seven polymorphisms were analysed, spanning functionally important regions of the insulin receptor locus. Four of these polymorphisms were mapped more accurately within the gene compared to previous studies. The genotype distribution was compared in 76 Type 2 diabetic patients and 84 healthy control subjects. No significant differences were found in the distribution of genotypes between diabetic and control subjects at the p less than 0.01 level. In order to study the possible association between quantitative measures of glucose metabolism and these DNA polymorphisms, the fasting glucose and insulin concentrations were compared in the different genotype groups of control subjects and mildly diabetic patients treated with diet. No differences in fasting glucose or insulin concentrations were found at the p less than 0.005 level of significance. In conclusion, no significant associations were found between insulin receptor gene DNA polymorphisms and glucose intolerance.

The gene for insulin-like growth factor-binding protein-1 is localized to human chromosomal region 7p14-p12.

Insulin-like growth factors (IGF) I and II are bound to high-affinity binding proteins in the blood circulation and other body fluids. These IGF-binding proteins are expressed at different concentrations in different tissues and are thought to regulate the activity of IGF I and II. Cloned cDNA for IGF-binding protein-1 (IGFBP1) has been used to verify the location of its gene to human chromosome 7 by Southern blotting to DNA from a human-mouse hybrid cell line. Further, by in situ hybridization the gene was regionally localized to 7p14-p12, and a Mendelian-inherited two-allele BglII restriction enzyme length polymorphism was identified, with the most frequent allele occurring in 53% of the chromosomes.

Human insulin-like growth-factor-binding protein. Low-molecular-mass form: protein sequence and cDNA cloning.

Two different insulin-like growth-factor (IGF)-binding proteins have been found in human blood, one of high molecular mass and dependent on growth hormone for synthesis, the other of low molecular mass and independent of growth hormone. The small IGF-binding protein is abundant in human amniotic fluid. Its amino acid sequence has now been determined by direct analysis of the protein and its proteolytic fragments. Also, by immunoscreening a partial cDNA clone was isolated from a human hepatoma cell line. The mature protein consists of 234 amino acids and is coded for by an mRNA of approximately 1700 nucleotides in length. The primary structure of the protein reveals 18 Cys residues in N-terminal and C-terminal clusters and an Arg-Gly-Asp peptide sequence, common to extracellular proteins binding to receptors of the integrin family. A protein-sequence polymorphism was detected at position Ile/Met-228, indicating possible allelic variation. The 3'-untranslated mRNA sequence has a high A + T content and shows five copies of an ATTTA sequence, which has been shown to be involved in the regulation of the stability of certain mRNAs coding for growth-regulating proteins.