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The chemokine CXCL12 and its shared seven-transmembrane receptors CXCR4 and CXCR7 regulate diseases including cancer, atherosclerosis, autoimmunity, and HIV infection, making these molecules promising drug targets. These molecules also control key processes in normal development and physiology, suggesting the need to selectively modulate CXCR4 and/or CXCR7 functions and signaling to reduce potential complications of long-term therapy. We previously identified two peptides that functioned as allosteric agonists driving CXCR4-dependent chemotaxis, providing key structural information to design a small number of additional peptides to investigate determinants of CXCL12 interactions and signaling through CXCR4 and CXCR7. In the current study, we show that the previously identified peptides only minimally activated CXCR4 signaling through the cytosolic adapter protein β-arrestin 2 and do not initiate signaling to ERK1/2. By comparison, peptides with diverse N-terminal amino acid sequences effectively activated CXCR7 signaling to β-arrestin 2. One peptide, designated as GSLW based on its N-terminal amino acids, activated CXCR7 signaling and potentiated CXCL12-CXCR7 signaling without blocking the scavenger function of CXCR7 to internalize CXCL12. These results advance our understanding of CXCR7 ligand recognition and signaling, and provide structural information to target allosteric binding sites on this receptor as chemical probes and potential therapeutic agents.  相似文献   
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The pharmacology, toxicokinetics, and safety of HematideTM, a synthetic peptidic erythropoiesis-stimulating agent (ESA), were characterized. Hematide was given intravenously (0, 0.5, 5, and 50 mg/kg) weekly for five weeks with a 6- (rat) and 12-week (monkey) recovery period. The pharmacological action of Hematide resulted in polycythemia. Histopathology consistent with drug-induced exaggerated pharmacology was observed primarily in rats. Secondary sequelae resulting from pronounced polycythemia was considered the cause of deaths in rats and a single high-dose monkey. Toxicokinetic analysis indicated prolonged exposure. In conclusion, Hematide is a potent ESA and the safety and efficacy profile support clinical development.  相似文献   
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Clear documentation of literature search and presentation methodologies can improve transparency in chemical hazard assessments. We sought to improve clarity for the scientific support for cancer mechanisms of action using a systematic approach to literature retrieval, selection, and presentation of studies. The general question was “What are the mechanisms by which a chemical may cause carcinogenicity in the target tissue?”. Di(2-ethylhexyl)phthalate was used as a case study chemical with a complex database of >3000 publications. Relevant mechanistic events were identified from published reviews. The PubMed search strategy included relevant synonyms and wildcards for DEHP and its metabolites, mechanistic events, and species of interest. Tiered exclusion/inclusion criteria for study pertinence were defined, and applied to the retrieved literature. Manual curation was conducted for mechanistic events with large literature databases. Literature trees documented identification and selection of the literature evidence. The selected studies were summarized in evidence tables accompanied by succinct narratives. Primary publications were deposited into the Health and Environmental Research Online (http://hero.epa.gov/) database and identified by pertinence criteria and key terms to permit organized retrieval. This approach contributes to human health assessment by effectively managing a large volume of literature, improving transparency, and facilitating subsequent synthesis of information across studies.  相似文献   
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Disturbed sleep affects multiple aspects of an individual's life, including daytime activity, social interactions, mood, and quality of life. Individuals with mental health issues often experience disturbed sleep, and particular attention must be given to underlying lifestyle, family issues, and health problems that may perpetuate a sleep complaint. In addition to patients' medical conditions, clinicians should ask patients about their sleep-wake patterns and medication use, since these factors contribute to disturbed sleep and adverse mental health outcomes. This article provides advanced practice nurses with a brief sleep assessment guide for use in psychiatric practice with adults or children.  相似文献   
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