Publications by authors named "Repke H"

Loss of control (LOC)-eating, excess weight, and anxiety are robustly linked, and are independently associated with markers of poorer cardiometabolic health, including hypertension. However, no study has examined whether frequency of LOC-eating episodes among youth with anxiety symptoms and elevated weight status may confer increased risk for hypertension. We examined the relationship between LOC-eating frequency and blood pressure among 39 adolescent girls (14.

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Adolescent military-dependents are an understudied population who face unique stressors due to their parents' careers. Research suggests that adolescent military-dependents report more anxiety and disordered-eating than their civilian counterparts. While anxiety symptoms predict the onset and worsening of disordered-eating attitudes, the mechanisms underlying this relationship remain unclear.

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(1) Background: Standard-of-care lifestyle interventions show insufficient effectiveness for the prevention and treatment of excess weight and its associated cardiometabolic health concerns in adolescents, necessitating more targeted preventative approaches. Anxiety symptoms are common among adolescents, especially girls at risk for excess weight gain, and have been implicated in the onset and maintenance of disinhibited eating. Thus, decreasing elevated anxiety in this subset of adolescent girls may offer a targeted approach to mitigating disinhibited eating and excess weight gain to prevent future cardiometabolic health problems.

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Purpose: Evidence suggests that difficulties identifying and describing one's feelings, core components of alexithymia, are associated with attitudinal and behavioral symptoms of disordered eating; depressive symptoms also may underlie these associations. Specifically, research indicates that alexithymia is positively related to depressive symptoms, which in turn may promote both disordered-eating attitudes and certain disinhibited-eating behaviors (e.g.

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The structural requirements for the selective binding of cholecystokinin-8 (CCK-8)-related peptides to peripheral (CCKA) receptors are not sufficiently understood. In this study, the interaction of a series of newly shortened analogues of CCK-8 with both receptor subtypes was analyzed by displacement studies using [3H]-CCK-8 and 125I-Bolton-Hunter (BH)-CCK-8 as radioligands. The pentapeptide derivative of CCK-8, succinyl-Tyr (SO3H)-Met-Gly-Trp-Met-phenethylamide, was found to bind selectively with high affinity to the CCKA receptor.

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CD4 serves as a receptor for major histocompatibility complex class II antigens and as a receptor for the human immunodeficiency virus type 1 (HIV-1) viral coat protein gp120. It is coupled to the protein-tyrosine kinase p56lck, an interaction necessary for an optimal response of certain T cells to antigen. In addition to the protein-tyrosine kinase domain, p56lck possesses Src homology 2 and 3 (SH2 and SH3) domains as well as a unique N-terminal region.

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CD4 serves as a receptor for MHC class II antigens and as a receptor for the human immunodeficiency virus (HIV-1) viral coat protein gp120. It is coupled to the protein-tyrosine kinase p56lck, an interaction necessary for an optimal response of certain T cells to antigen. Although anti-CD4 crosslinking may increase lck activity, the effects of HIV-1 gp120 have been controversial.

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Deletions of the major variable regions (V1/V2, V3, and V4) of the human immunodeficiency virus type 1 (HIV-1) gp120 exterior envelope glycoprotein were created to study the role of these regions in function and antigenicity. Deletion of the V4 region disrupted processing of the envelope glycoprotein precursor. In contrast, the deletion of the V1/V2 and/or V3 regions yielded processed exterior envelope glycoproteins that retained the ability to interact with the gp41 transmembrane glycoprotein and the CD4 receptor.

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Changes were introduced into conserved amino acids within the ectodomain of the human immunodeficiency virus type 1 (HIV-1) gp41 transmembrane envelope glycoprotein. The effect of these changes on the structure and function of the HIV-1 envelope glycoproteins was examined. The gp41 glycoprotein contains an amino-terminal fusion peptide (residues 512 to 527) and a disulfide loop near the middle of the extracellular domain (residues 598 to 604).

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The CD4 cell surface antigen belongs to the immunoglobulin superfamily and is the primary receptor for the human immunodeficiency virus 1 (HIV-1). The high affinity interaction between HIV-1 and CD4 is mediated by the viral envelope glycoprotein gp120. Recombinant soluble CD4 (rsCD4) has been shown in vitro to be an effective inhibitor of HIV-1 and HIV-2 propagation in lymphoid cells.

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Gangliosides induce a selective and complete modulation of CD4 from the surface of T cells. CD4 down-modulation occurs by CD4 endocytosis. This process is independent of serine phosphorylation of the cytoplasmic tail of CD4 and does not require the association between the tyrosine protein kinase p56lck and the cytoplasmic tail of CD4.

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The noncovalent association of the gp120 and gp41 envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) is disrupted by soluble CD4 binding, resulting in shedding of the gp120 exterior envelope glycoprotein. This observation has led to the speculation that interaction of gp120 with the CD4 receptor triggers shedding of the exterior envelope glycoprotein, allowing exposure of gp41 domains necessary for membrane fusion steps involved in virus entry or syncytium formation. To test this hypothesis, a set of HIV-1 envelope glycoprotein mutants were used to examine the relationship of soluble CD4-induced shedding of the gp120 glycoprotein to envelope glycoprotein function in syncytium formation and virus entry.

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Benzylated derivatives of a peptide (CD4(81-92)) representing the CDR3-like region of CD4 were previously found to inhibit gp120 binding, HIV-1 infectivity, and syncytium formation. These results have been interpreted to indicate a role for the corresponding CD4 region in these processes. The peptide (TbYICbEbVEDQKAcEE) is the prototype of a series of similar CD4(81-92) derivatives.

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We investigated the binding affinity of new tetrapeptides derived from the C-terminal sequence of CCK8 to central CCKB and peripheral CCKA receptors. Compound 1 (Boc-Trp-Met-Asp-Phe-NH2) showed high affinity for central CCKB receptors (Ki 4.2 x 10(-8) M, pancreas/cortex ratio = 283).

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The nonselective antagonist [3H]naloxone was used to identify opioid receptors in rat brain membranes. The multiple naloxone binding sites were related to different opioid receptors by means of selective opioid ligands as well as various beta-casomorphin analogues. Analysis of binding site heterogeneity was performed using several computer curve fitting methods.

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Histamine was released from mast cells in isolated perfused heart and kidney of the rat, but not from mast cells in guinea-pig tissues, by a substance P (SP) analogue (SP(1-4)-NH-C12H25), SP(1-4)-C12 for abbreviation. This peptide also released histamine from peritoneal mast cells and basophil leucocytes of the rat. Substance P itself was compared with SP(1-4)-C12 and some structurally related peptides and showed weaker activity.

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Mouse spleen cells were incubated for 24 hours in the presence of histamine (10(-13)-10(-3) M). Aliquots of the histamine free supernatants were intravenously injected into either syngenic or allogenic mice which were subsequently analysed by the Jerne plaque assay in respect of their specific IgM response against red blood cells from sheep. Depending on the histamine concentration during the preincubation and the mouse strain, the effects of the supernatants were found to be suppressive or potentiating.

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The immunomodulatory actions of histamine in mice were examined by a combined in vitro/in vivo approach. Spleen cells from mice were incubated between 2 and 24 hours with histamine (10(-12)-10(-3) M) under conditions which prevent a change of the free histamine concentration. The cells were subsequently transferred to sublethally irradiated syngenic mice in order to measure the adoptive IgM response.

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Experiments were based on the hypothesis that the histamine releasing action of substance P and some other neuropeptides is not due to the interaction of the neuropeptide with a specific membrane receptor. Rather, this may be a property of many amphiphilic compounds having a minimal number of positives charges and a hydrophobic chain which is not necessarily a peptide. According to this hypothesis, 18 substance P derivatives and fragments were synthesized and tested on rat and hamster peritoneal mast cells, among them five compounds which contain a non-peptide chain instead of the C-terminal substance P heptapeptide.

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The substance Arg-Pro-Lys-Pro-(CH2)11CH3 [SP1-4C12] was synthesized by forming a peptide bond between Arg-Pro-Lys-Pro, the N-terminal sequence of substance P and dodecylamine. The aim was to examine the roles of the N- and C-terminal sequences of substance P in stimulating histamine release from mast cells of the rat peritoneal cavity. SP1-4 C12 induces concentration-dependent histamine release in the range 8 to 200 nM.

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Substance P is a representative of a group of amphiphilic neuropeptides which act as mast cell secretagogues. Our experiments with some new substance P derivatives suggest that these effects are dependent on two structural elements: (i) a hydrophobic chain which is not essentially a peptide, and (ii) a hydrophilic part with two positively charged amino acids. The mast cell triggering effect is unlikely to be mediated by a selective substance P receptor, but has strong similarities to the mode of action of polycations.

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The physical properties of the covalently labeled [( 3H]propylbenzilycholine mustard) muscarinic acetylcholine receptor from rat brain were studied by sodium dodecyl sulfate-polyacrylamide electrophoresis and computer-assisted Ferguson plot analysis. No proteolytic degradation or dimerization of the ligand binding subunit was found. No clues for different molecular weight forms or anomalous migration of the muscarinic receptor were detected.

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Muscarinic receptors were solubilized by nonionic, zwitterionic and ionic detergents from porcine striatum. A mixture of digitonin and gitonin (3:2) was found to be most suitable in respect to receptor yield and stability. The solubilization of muscarinic receptors by this detergent appears to be dependent on the existence of free detergent micelles.

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Four monoclonal mouse anti rat mast cell antibodies were selected which detect an antigenic determinant occurring on connective tissue mast cells of the rat. A strong antigen density was found on peritoneal mast cells whereas pleural and mesenteric mast cells exhibit considerably smaller amounts of the antigen. It does not occur on lung mast cells and basophils, thus permitting a mast cell subtype differentiation according to the expression of a surface antigen.

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Selye found that in response to different stressors the body reacts with a characteristic stress syndrome: adrenal enlargement, gastrointestinal ulcera, and thymicolymphatic involution. In this paper we demonstrate that i.p.

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