Browsing by Subject "Imidazoles"

Now showing 1 - 4 of 4
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    Astroglial tracer BU99008 detects multiple binding sites in Alzheimer's disease brain
    (Springer Nature, 2021) Kumar, Amit; Koistinen, Niina A.; Malarte, Mona-Lisa; Nennesmo, Inger; Ingelsson, Martin; Ghetti, Bernardino; Lemoine, Laetitia; Nordberg, Agneta; Pathology and Laboratory Medicine, School of Medicine
    With reactive astrogliosis being established as one of the hallmarks of Alzheimer's disease (AD), there is high interest in developing novel positron emission tomography (PET) tracers to detect early astrocyte reactivity. BU99008, a novel astrocytic PET ligand targeting imidazoline-2 binding sites (I2BS) on astrocytes, might be a suitable candidate. Here we demonstrate for the first time that BU99008 could visualise reactive astrogliosis in postmortem AD brains and propose a multiple binding site [Super-high-affinity (SH), High-affinity (HA) and Low-affinity (LA)] model for BU99008, I2BS specific ligands (2-BFI and BU224) and deprenyl in AD and control (CN) brains. The proportion (%) and affinities of these sites varied significantly between the BU99008, 2-BFI, BU224 and deprenyl in AD and CN brains. Regional binding studies demonstrated significantly higher 3H-BU99008 binding in AD brain regions compared to CN. Comparative autoradiography studies reinforced these findings, showing higher specific binding for 3H-BU99008 than 3H-Deprenyl in sporadic AD brain compared to CN, implying that they might have different targets. The data clearly shows that BU99008 could detect I2BS expressing reactive astrocytes with good selectivity and specificity and hence be a potential attractive clinical astrocytic PET tracer for gaining further insight into the role of reactive astrogliosis in AD.
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    DNA Targeting as a Likely Mechanism Underlying the Antibacterial Activity of Synthetic Bis-Indole Antibiotics
    (American Society for Microbiology, 2016-11-21) Opperman, Timothy J.; Kwasny, Steven M.; Bo Li, Jessica; Lewis, Mark A.; Aiello, Daniel; Williams, John D.; Peet, Norton P.; Moir, Donald T.; Bowlin, Terry L.; Long, Eric C.; Chemistry and Chemical Biology, School of Science
    We previously reported the synthesis and biological activity of a series of cationic bis-indoles with potent, broad-spectrum antibacterial properties. Here, we describe mechanism of action studies to test the hypothesis that these compounds bind to DNA and that this target plays an important role in their antibacterial outcome. The results reported here indicate that the bis-indoles bind selectively to DNA at A/T-rich sites, which is correlated with the inhibition of DNA and RNA synthesis in representative Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) organisms. Further, exposure of E. coli and S. aureus to representative bis-indoles resulted in induction of the DNA damage-inducible SOS response. In addition, the bis-indoles were found to be potent inhibitors of cell wall biosynthesis; however, they do not induce the cell wall stress stimulon in S. aureus, suggesting that this pathway is inhibited by an indirect mechanism. In light of these findings, the most likely basis for the observed activities of these compounds is their ability to bind to the minor groove of DNA, resulting in the inhibition of DNA and RNA synthesis and other secondary effects.
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    Influence of Zoledronic Acid on Atrial Electrophysiological Parameters and Electrocardiographic Measurements
    (Wiley Blackwell (John Wiley & Sons), 2015-06) Tisdale, James E.; Allen, Matthew R.; Overholser, Brian R.; Jaynes, Heather A.; Kovacs, Richard J.; Department of Anatomy & Cell Biology, IU School of Medicine
    INTRODUCTION: Our objective was to determine effects of zoledronic acid (ZA) on atrial electrophysiological parameters and electrocardiographic measurements. METHODS AND RESULTS: Ex vivo perfusion study: Isolated guinea pig hearts were perfused with modified Krebs-Henseleit (K-H) buffer with or without ZA 0.07 mg/kg/L (each n = 6). In ZA-perfused hearts, atrial action potential at 90% repolarization (APD90 ) decreased more from baseline than in controls (-23.2% ± -5.1% vs. -2.1% ± -8.1%, P < 0 .0001), as did APD30 (-28.8% ± -3.8% vs. -2.1% ± -2.1%, P < 0.0001). In vivo dose-response study: Guinea pigs underwent intraperitoneal injections every 2 weeks in 1 of 4 groups (each n = 8): ZA 0.007 mg/kg (low-dose), ZA 0.07 mg/kg (medium-dose), ZA 0.7 mg/kg (high-dose), or placebo. Hearts were excised at 8 weeks and perfused with modified K-H. Atrial effective refractory period (ERP) was lower with medium- and high-dose ZA versus placebo (P = 0.004). Atrial APD30 was lower with high-dose ZA versus placebo, low and medium doses (P < 0.001). Canine ECG study: Mature female beagles received intravenous ZA 0.067 mg/kg or saline (placebo; each n = 6) every 2 weeks for 12 weeks. P wave dispersion was greater in the ZA group (7.7 ± 3.7 vs. 3.4 ± 2.6 ms, P = 0.04). There were no significant differences in P wave index, maximum or minimum P wave duration, or PR interval. CONCLUSION: ZA shortens left atrial APD and ERP and increases P wave dispersion.
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    International Myeloma Working Group recommendations for the treatment of multiple myeloma-related bone disease
    (American Society of Clinical Oncology, 2013-06-20) Terpos, Evangelos; Morgan, Gareth; Dimopoulos, Meletios A.; Drake, Matthew T.; Lentzsch, Suzanne; Raje, Noopur; Sezer, Orhan; Garcıa-Sanz, Ramon; Shimizu, Kazuyuki; Turesson, Ingemar; Reiman, Tony; Jurczyszyn, Artur; Merlini, Giampaolo; Spencer, Andrew; Leleu, Xavier; Cavo, Michele; Munshi, Nikhil; Rajkumar, S. Vincent; Durie, Brian G.M.; Roodman, G. David; Department of Medicine, IU School of Medicine
    PURPOSE: The aim of the International Myeloma Working Group was to develop practice recommendations for the management of multiple myeloma (MM) -related bone disease. METHODOLOGY: An interdisciplinary panel of clinical experts on MM and myeloma bone disease developed recommendations based on published data through August 2012. Expert consensus was used to propose additional recommendations in situations where there were insufficient published data. Levels of evidence and grades of recommendations were assigned and approved by panel members. RECOMMENDATIONS: Bisphosphonates (BPs) should be considered in all patients with MM receiving first-line antimyeloma therapy, regardless of presence of osteolytic bone lesions on conventional radiography. However, it is unknown if BPs offer any advantage in patients with no bone disease assessed by magnetic resonance imaging or positron emission tomography/computed tomography. Intravenous (IV) zoledronic acid (ZOL) or pamidronate (PAM) is recommended for preventing skeletal-related events in patients with MM. ZOL is preferred over oral clodronate in newly diagnosed patients with MM because of its potential antimyeloma effects and survival benefits. BPs should be administered every 3 to 4 weeks IV during initial therapy. ZOL or PAM should be continued in patients with active disease and should be resumed after disease relapse, if discontinued in patients achieving complete or very good partial response. BPs are well tolerated, but preventive strategies must be instituted to avoid renal toxicity or osteonecrosis of the jaw. Kyphoplasty should be considered for symptomatic vertebral compression fractures. Low-dose radiation therapy can be used for palliation of uncontrolled pain, impending pathologic fracture, or spinal cord compression. Orthopedic consultation should be sought for long-bone fractures, spinal cord compression, and vertebral column instability.