Publications by authors named "Oehlke J"

Study Objectives: To evaluate the type and extent of information collected from patients with insomnia during their first office encounter for insomnia and the prescribing therapies of primary care providers during this initial encounter.

Methods: This study was a retrospective chart review of randomly selected patients who had a primary care provider office visit at any clinic affiliated with a university medical system between March 1, 2013, and March 1, 2016. Demographic and clinical information was abstracted for analysis.

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Template models of legged locomotion are powerful tools for gait analysis, but can also inspire robot design and control. In this paper, a spring-loaded inverted pendulum (SLIP) model is employed to control vertical hopping of a 2-segmented legged robot. Feed-forward and bio-inspired virtual model control using the SLIP model are compared.

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Purpose: Cancer immunotherapy offers hope of a highly specific nontoxic adjuvant treatment. Heat shock protein peptide complexes (HSPPCs) found in cancer cells carry tumor-specific antigenic proteins and can facilitate adaptive and innate immune responses. Here we show that peptides bound to a 96 kD chaperone protein (HSP-96) from brain tissue containing glioblastoma multiforme (GBM) can be used to safely immunize patients with recurrent GBM.

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Evidence is presented that components of fetal calf serum (FCS) can significantly enhance the splicing correction activity of peptide nucleic acids (PNA) in HeLa pLuc 705 cells. The effect proved more pronounced for PNAs bearing fluorescence tags and relies on the ability of specific components of FCS to mediate a mainly nonendocytotic intracellular delivery of PNA. Attempts to isolate and characterize the active serum components using PNA-loaded beads and nano-LC-ESI mass spectrometry revealed the growth-factor related inter-alpha-trypsin inhibitor and the adhesion protein fibronectin to be substantially responsible for the delivery activity of FCS.

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The ability of peptide nucleic acids (PNA) to enter and to cross filter-grown MDCK, HEK and CHO cells was studied by means of a protocol based on capillary electrophoresis combined with laser-induced fluorescence detection. The used approach avoided possible errors encountered in protocols based on confocal laserscanning microscopy and FACS analysis. In contradiction to the commonly anticipated unability of PNA to cross biomembranes, extensive translocation of unmodified PNA into and across the investigated cell types was found.

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A 12-mer peptide nucleic acid (PNA) directed against the nociceptin/orphanin FQ receptor mRNA was disulfide bridged with various peptides without and with cell-penetrating features. The cellular uptake and the antisense activity of these conjugates were assessed in parallel. Quantitation of the internalized PNA was performed by using an approach based on capillary electrophoresis with laser-induced fluorescence detection (CE-LIF).

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Peptide nucleic acids (PNAs) have shown great promise as potential antisense drugs; however, poor cellular delivery limits their applications. Improved delivery into mammalian cells and enhanced biological activity of PNAs have been achieved by coupling to cell-penetrating peptides (CPPs). Structural requirements for the shuttling ability of these peptides as well as structural properties of the conjugates such as the linker type and peptide position remained controversial, so far.

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This study provides the first evidence that actin reorganization during AQP2 vesicular trafficking to the plasma membrane requires the functional involvement of ERM (ezrin/radixin/moesin) proteins cross-linking actin filaments with plasma membrane proteins. We report that forskolin stimulation was associated with a redistribution of moesin from intracellular sites to the cell cortex and with a concomitant enrichment of moesin in the particulate fraction in renal cells. Introduction of a peptide reproducing a short sequence of moesin within the binding site for F-actin induced all the key effects of forskolin stimulation, including a decrease in F-actin, translocation of endogenous moesin, and AQP2 translocation.

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The influence of the peptide-to-cell ratio and energy depletion on uptake and degradation of the cell-penetrating peptides (CPPs) MAP (model amphipathic peptide) was investigated. The intracellular concentration of the CPPs, MAP and penetratin was monitored while varying the number of cells at fixed peptide concentration and incubation volume, or changing the concentration and incubation volume at fixed cell number. The uptake of CPPs was shown to be dependent on the peptide/cell ratio.

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In the last decade many peptides have been shown to be internalized into various cell types by different, poorly characterized mechanisms. This review focuses on uptake studies with substance P (SP) aimed at unravelling the mechanism of peptide-induced mast cell degranulation, and on the characterization of the cellular uptake of designed KLA-derived model peptides. Studies on structure-activity relationships and receptor autoradiography failed to detect specific peptide receptors for the undecapeptide SP on mast cells.

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In order to evaluate the ability of the cell-penetrating alpha-helical amphipathic model peptide KLALKLALKALKAALKLA-NH(2) (MAP) to deliver peptide nucleic acids (PNAs) into mammalian cells, MAP was covalently linked to the 12-mer PNA 5'-GGAGCAGGAAAG-3' directed against the mRNA of the nociceptin/orphanin FQ receptor. The cellular uptake of both the naked PNA and its MAP-conjugate was studied by means of capillary electrophoresis combined with laser-induced fluorescence detection, confocal laser scanning microscopy and fluorescence-activated cell sorting. Incubation with the fluorescein-labelled PNA-peptide conjugate led to three- and eightfold higher intracellular concentrations in neonatal rat cardiomyocytes and CHO cells, respectively, than found after exposure of the cells to the naked PNA.

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The uptake by mammalian cells of phosphorothioate oligonucleotides was compared with that of their respective complexes or conjugates with cationic, cell-penetrating model peptides of varying helix-forming propensity and amphipathicity. An HPLC-based protocol for the synthesis and purification of disulfide bridged conjugates in the 10-100 nmol range was developed. Confocal laser scanning microscopy (CLSM) in combination with gel-capillary electrophoresis and laser induced fluorescence detection (GCE-LIF) revealed cytoplasmic and nuclear accumulationin all cases.

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The cellular uptake of a peptide set derived from membrane-permeable alpha-helical amphipathic peptides by stepwise alterations of structure forming propensity and charge was studied by confocal laser scanning microscopy (CLSM) combined with HPLC. For CLSM monitoring, an online protocol was employed that avoided bias of the uptake results by washout. Using this protocol, extensive fluorescence, approaching the intensity of the external peptide, was observed in the cytosol and nucleus within minutes in all cases, irrespective of the degree of amphipathicity.

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The structure of the cell-permeable alpha-helical amphipathic model peptide FLUOS-KLALKLALKALKAALKLA-NH2 (I) was modified stepwise with respect to its helix parameters hydrophobicity, hydrophobic moment and hydrophilic face as well as molecular size and charge. Cellular uptake and membrane destabilizing activity of the resulting peptides were studied using aortic endothelial cells and HPLC combined with CLSM. With the exceptions that a reduction of molecule size below 16 amino acid residues and the introduction of a negative net charge abolished uptake, none of the investigated structural parameters proved to be essential for the passage of these peptides across the plasma membrane.

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Evidence that multiple, probably non-endocytic mechanisms are involved in the uptake into mammalian cells of the alpha-helical amphipathic model peptide FLUOS-KLALKLALKALKAALKLA-NH2 (I) is presented. Extensive cellular uptake of N-terminally GC-elongated derivatives of I, conjugated by disufide bridges to differently charged peptides, indicated that I-like model peptides might serve as vectors for intracellular delivery of polar bioactive compounds. The mode of the cellular internalization of I comprising energy-, temperature-, pH- and ion-dependent as well as -independent processes suggests analogy to that displayed by small unstructured peptides reported previously (Oehlke et al.

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After exposure of bovine aortic endothelial cells to various small peptides (tetra- to undeca-mer), extensive transport of the peptides across the plasma membrane was observed in the concentration range 10(-7) to 10(-2) M. The observed transport events, which contradict the generally anticipated poor permeability of peptides across plasma membranes, exhibited high complexity and showed no saturability up to a concentration of 10(-2) M. Evidence was found for the involvement of mdrp-like transporters as well as of energy-independent facilitated diffusion events.

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Extensive internalization into endothelial cells has been found for a water soluble amphipathic 26-mer beta-sheet peptide (FLUOS-DPKGDPKGVTVTVTVTVTGKGDPKPD-NH2; VT5). With the D-Val13,D-Thr14 di-D-amino acid analog of VT5 (DD-VT5), exhibiting an identical primary structure but no propensity to adopt a beta-sheet conformation, only about 5% of the cellular uptake of VT5 was found. The mechanism of entry of VT5 into the cells remained unclear, but proved to be energy, temperature and pH dependent and, therefore, clearly distinct from that reported for helical amphipathic peptides.

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The disposition of the gonadotropin-releasing hormone (GnRH) agonist buserelin was studied in male rats under conditions of long-term administration. Rats were continuously infused with about 30 pmole [3H]-buserelin/24 h subcutaneously by osmotic minipumps for 4-7 days. After killing the rats, the 3H-activity of the tissues was measured and was found to be highly concentrated (about 10-fold to plasma) only in the pituitary.

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A precolumn benzoylation for analyzing sugars, polyols and neutral amino acids in biological fluids by high-performance liquid chromatography has been developed, which avoids protein precipitation, drying procedures and the use of pyridine. Derivatization and chromatography can be performed within one hour with a minimum detectable quantity of ca. 1 pmol (signal-to-noise ratio > 2).

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The short-time disposition of 3H-labeled D-Ser(TBU)6-desGly10-GnRH-ethylamide ([3H]buserelin) was studied in rats after bolus intravenous and subcutaneous injections and killing the rats after 1 and 3 hr, respectively. When estimated as the percentage of the injected dose, 3H-activity within the whole blood rapidly declined from 25.5% at 2 min to 4.

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There are two types of superactive agonists of gonadotropin-releasing hormone (GnRHa-I: (D-amino acid)6-GnRH and GnRHa-II: (D-amino acid)6-(desGly)10-GnRH- ethylamide) the high hormonal activity of which is understood to be due to their higher receptor affinity and their higher proteolytic stability as compared with the native GnRH sequence. Using the soluble fractions of various rat tissues in studies on the inactivation of GnRH peptides, we confirmed the higher proteolytic resistance of GnRHa-II, but not of D-Phe6-GnRH (GnRHa-I) and of another analog, D-Trp3-D-Phe6-GnRH, as compared with GnRH. The exact behaviour of the peptides during degradation was found to be dependent on the peptide concentrations used, showing the importance of using conditions as near to the physiological ones a possible.

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The authors determined the dissociation constant, the constant of copper complex formation, the inhibitory action on the catecholamine biosynthesis enzyme dopamine beta-hydroxylase (DBH; copper glycoprotein), as well as the antihypertensive effect on spontaneously hypertensive rats of a series of substituted picolinic or fusaric acids (FA; 5-n-butylpicolinic acids). The substances investigated may be characterized as weak to medium-strong acids which form stable copper(II) complexes in solution and in the solid state. The concentrations required for a 50% inhibition of DBH range between 10(-6) and 10(-5) mol/l.

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It has been found that desoxycholic acid-3- (1), -12- (2) and -3,12-bis-beta-D-glucuronide (3) exert a potent allosteric effect on the beta-glucuronidase activity, which results in non-competitive inhibition of this enzyme in the pH range from 4.5 to nearly 5.5, and in its activation in the pH range from 6 to 7.

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