Publications by authors named "Zhimeng Zhu"

Background: Pharmacotherapies targeting motivational aspects of feeding and palatable food reward, while sparing mood and cognitive function, represent an alluring approach to reverse obesity and maintain weight loss in an obesogenic environment. A novel glucagon-like peptide-1/dexamethasone (GLP-1/Dexa) conjugate, developed to selectively activate glucocorticoid receptors in GLP-1 receptor-expressing cells was shown to decrease food intake and lower body weight in obese mice. Here, we investigate if this novel drug candidate modulates the rewarding properties of food and if it affects behavioral indices of mood and memory.

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Objective: Upon activation, G protein coupled receptors (GPCRs) associate with heterotrimeric G proteins at the plasma membrane to initiate second messenger signaling. Subsequently, the activated receptor experiences desensitization, internalization, and recycling back to the plasma membrane, or it undergoes lysosomal degradation. Recent reports highlight specific cases of persistent cyclic AMP generation by internalized GPCRs, although the functional significance and mechanistic details remain to be defined.

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Chronic inflammation has been proposed to contribute to the pathogenesis of diet-induced obesity. However, scarce therapeutic options are available to treat obesity and the associated immunometabolic complications. Glucocorticoids are routinely employed for the management of inflammatory diseases, but their pleiotropic nature leads to detrimental metabolic side effects.

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Glucagon and thyroid hormone (T) exhibit therapeutic potential for metabolic disease but also exhibit undesired effects. We achieved synergistic effects of these two hormones and mitigation of their adverse effects by engineering chemical conjugates enabling delivery of both activities within one precisely targeted molecule. Coordinated glucagon and T actions synergize to correct hyperlipidemia, steatohepatitis, atherosclerosis, glucose intolerance, and obesity in metabolically compromised mice.

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A simple and reproducible high performance liquid chromatography-tandem mass spectrometric method was developed for methocarbamol analysis in human plasma. Methocarbamol and the internal standard (IS) were extracted by a protein precipitation method. Under isocratic separation condition the chromatographic run time was 3.

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This event was organized by the Calibration and Validation Group (a scientific nonprofit organization based in Toronto, Canada) as a 1.5-day workshop for contract research organizations and pharmaceutical companies involved in providing bioanalytical data for bioavailability, bioequivalence, pharmacokinetic and comparability studies.

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A new method, using high-performance liquid chromatography/ion electrospray (negative ion) mass spectrometry, has been developed for the determination of a hydrophilic liver-specific inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase, pravastatin in human plasma. In this method, plasma samples were prepared by a solid-phase extraction on C(18) Bond Elut cartridge. Chromatography was carried out with a Zorbax C(8) column.

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A rapid and specific liquid chromatographic mass spectrometric (LC-MS-MS) method has been developed for the determination of paroxetine in human plasma. The procedure involves a liquid-liquid extraction of paroxetine and fluoxetine (internal standard) with cyclohexane-ethyl acetate. The standard curve was linear over a working range of 0.

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A fast and robust liquid chromatography-mass spectrometry (LC-MS-MS) method has been developed for simultaneous quantitation of the angiotensin-converting enzyme (ACE) inhibitor, ramipril and its metabolite ramiprilat in human plasma. The method involves a solid-phase extraction from plasma, simple isocratic chromatography conditions and mass spectrometric detection that enables a detection limit at sub-nanogram levels. The proposed method has been validated with a linear range of 0.

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