The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Kathryn A Taubert - One of the best experts on this subject based on the ideXlab platform.
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prevention of rheumatic fever and diagnosis and treatment of acute streptococcal pharyngitis a scientific statement from the american heart association rheumatic fever endocarditis and kawasaki disease committee of the council on cardiovascular disea
Circulation, 2009Co-Authors: Michael A Gerber, Stanford T Shulman, Anne H Rowley, Robert S Baltimore, Charles B Eaton, Michael H Gewitz, Kathryn A TaubertAbstract:Primary prevention of acute rheumatic fever is accomplished by proper identification and adequate antibiotic treatment of group A β-hemolytic streptococcal (GAS) tonsillopharyngitis. Diagnosis of GAS pharyngitis is best accomplished by combining clinical judgment with diagnostic test results, the criterion standard of which is the throat culture. Penicillin (either oral penicillin V or injectable benzathine penicillin) is the treatment of choice, because it is cost-effective, has a narrow spectrum of activity, and has long-standing proven efficacy, and GAS resistant to penicillin have not been documented. For penicillin-allergic individuals, acceptable alternatives include a narrow-spectrum oral cephalosporin, oral clindamycin, or various oral macrolides or Azalides. The individual who has had an attack of rheumatic fever is at very high risk of developing recurrences after subsequent GAS pharyngitis and needs continuous antimicrobial prophylaxis to prevent such recurrences (secondary prevention). The recommended duration of prophylaxis depends on the number of previous attacks, the time elapsed since the last attack, the risk of exposure to GAS infections, the age of the patient, and the presence or absence of cardiac involvement. Penicillin is again the agent of choice for secondary prophylaxis, but sulfadiazine or a macrolide or Azalide are acceptable alternatives in penicillin-allergic individuals. This report updates the 1995 statement by the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee. It includes new recommendations for the diagnosis and treatment of GAS pharyngitis, as well as for the secondary prevention of rheumatic fever, and classifies the strength of the recommendations and level of evidence supporting them.
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prevention of rheumatic fever and diagnosis and treatment of acute streptococcal pharyngitis a scientific statement from the american heart association rheumatic fever endocarditis and kawasaki disease committee of the council on cardiovascular disea
Circulation, 2009Co-Authors: Michael A Gerber, Stanford T Shulman, Anne H Rowley, Robert S Baltimore, Charles B Eaton, Michael H Gewitz, Kathryn A TaubertAbstract:Primary prevention of acute rheumatic fever is accomplished by proper identification and adequate antibiotic treatment of group A beta-hemolytic streptococcal (GAS) tonsillopharyngitis. Diagnosis of GAS pharyngitis is best accomplished by combining clinical judgment with diagnostic test results, the criterion standard of which is the throat culture. Penicillin (either oral penicillin V or injectable benzathine penicillin) is the treatment of choice, because it is cost-effective, has a narrow spectrum of activity, and has long-standing proven efficacy, and GAS resistant to penicillin have not been documented. For penicillin-allergic individuals, acceptable alternatives include a narrow-spectrum oral cephalosporin, oral clindamycin, or various oral macrolides or Azalides. The individual who has had an attack of rheumatic fever is at very high risk of developing recurrences after subsequent GAS pharyngitis and needs continuous antimicrobial prophylaxis to prevent such recurrences (secondary prevention). The recommended duration of prophylaxis depends on the number of previous attacks, the time elapsed since the last attack, the risk of exposure to GAS infections, the age of the patient, and the presence or absence of cardiac involvement. Penicillin is again the agent of choice for secondary prophylaxis, but sulfadiazine or a macrolide or Azalide are acceptable alternatives in penicillin-allergic individuals. This report updates the 1995 statement by the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee. It includes new recommendations for the diagnosis and treatment of GAS pharyngitis, as well as for the secondary prevention of rheumatic fever, and classifies the strength of the recommendations and level of evidence supporting them.
Raymond B Johnson - One of the best experts on this subject based on the ideXlab platform.
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a controlled trial of a single dose of azithromycin for the treatment of chlamydial urethritis and cervicitis
Obstetrical & Gynecological Survey, 1993Co-Authors: David H Martin, Ziad A Dalu, Tomasz F Mroczkowski, James Mccarty, Scott J Hopkins, Robert B. Jones, Raymond B JohnsonAbstract:Abstract Background. Currently, there is no single-dose therapy that is effective in the treatment of urethral or endocervical infections with Chlamydia trachomatis. Azithromycin is a new Azalide antibiotic that has substantial activity against C. trachomatis, is concentrated intracellularly, and has a long half-life in serum and tissue. Methods. We conducted a trial in which 299 female patients and 158 male patients with uncomplicated genital infection and a positive C. trachomatis antigen test were randomly assigned to receive either azithromycin (1 g once orally) or doxycycline (100 mg orally twice daily for seven days). Only patients subsequently determined to have a culture positive for C. trachomatis at base line were included in the evaluation of efficacy. Results. Among the patients who could be evaluated, 5 of the 141 patients (4 percent) treated with azithromycin did not respond to treatment, as compared with 3 of the 125 patients (2 percent) treated with doxycycline (difference between groups, ...
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a controlled trial of a single dose of azithromycin for the treatment of chlamydial urethritis and cervicitis
The New England Journal of Medicine, 1992Co-Authors: David H Martin, Ziad A Dalu, Tomasz F Mroczkowski, James Mccarty, Scott J Hopkins, Robert B. Jones, Raymond B JohnsonAbstract:BACKGROUND: Currently, there is no single-dose therapy that is effective in the treatment of urethral or endocervical infections with Chlamydia trachomatis. Azithromycin is a new Azalide antibiotic that has substantial activity against C. trachomatis, is concentrated intracellularly, and has a long half-life in serum and tissue. METHODS: We conducted a trial in which 299 female patients and 158 male patients with uncomplicated genital infection and a positive C. trachomatis antigen test were randomly assigned to receive either azithromycin (1 g once orally) or doxycycline (100 mg orally twice daily for seven days). Only patients subsequently determined to have a culture positive for C. trachomatis at base line were included in the evaluation of efficacy. RESULTS: Among the patients who could be evaluated, 5 of the 141 patients (4 percent) treated with azithromycin did not respond to treatment, as compared with 3 of the 125 patients (2 percent) treated with doxycycline (difference between groups, 2 percent; 95 percent confidence interval, 0 to 6 percent). Of the patients evaluated 21 to 35 days after treatment, none of 112 treated with azithromycin and 1 of 102 treated with doxycycline had a positive culture. The rates of bacteriologic cure were similar for the 98 female patients (97 percent) and the 43 male patients (95 percent) treated with azithromycin. Seventeen percent of the patients who received azithromycin and 20 percent of those treated with doxycycline had mild-to-moderate drug-related side effects, mainly gastrointestinal symptoms. CONCLUSIONS: A single 1-g dose of azithromycin is as effective for the treatment of uncomplicated genital chlamydial infections as a standard seven-day course of doxycycline.
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a controlled trial of a single dose of azithromycin for the treatment of chlamydial urethritis and cervicitis
The New England Journal of Medicine, 1992Co-Authors: David H Martin, Ziad A Dalu, Tomasz F Mroczkowski, James Mccarty, Scott J Hopkins, Robert B. Jones, Raymond B JohnsonAbstract:BACKGROUND: Currently, there is no single-dose therapy that is effective in the treatment of urethral or endocervical infections with Chlamydia trachomatis. Azithromycin is a new Azalide antibiotic that has substantial activity against C. trachomatis, is concentrated intracellularly, and has a long half-life in serum and tissue. METHODS: We conducted a trial in which 299 female patients and 158 male patients with uncomplicated genital infection and a positive C. trachomatis antigen test were randomly assigned to receive either azithromycin (1 g once orally) or doxycycline (100 mg orally twice daily for seven days). Only patients subsequently determined to have a culture positive for C. trachomatis at base line were included in the evaluation of efficacy. RESULTS: Among the patients who could be evaluated, 5 of the 141 patients (4 percent) treated with azithromycin did not respond to treatment, as compared with 3 of the 125 patients (2 percent) treated with doxycycline (difference between groups, 2 percent; 95 percent confidence interval, 0 to 6 percent). Of the patients evaluated 21 to 35 days after treatment, none of 112 treated with azithromycin and 1 of 102 treated with doxycycline had a positive culture. The rates of bacteriologic cure were similar for the 98 female patients (97 percent) and the 43 male patients (95 percent) treated with azithromycin. Seventeen percent of the patients who received azithromycin and 20 percent of those treated with doxycycline had mild-to-moderate drug-related side effects, mainly gastrointestinal symptoms. CONCLUSIONS: A single 1-g dose of azithromycin is as effective for the treatment of uncomplicated genital chlamydial infections as a standard seven-day course of doxycycline.
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the role of Azalide antibiotics in the treatment of chlamydia
American Journal of Obstetrics and Gynecology, 1991Co-Authors: Raymond B JohnsonAbstract:Chlamydia trachomatis causes an estimated 4 million infections each year in the United States. Sequelae in women include infertility and ectopic pregnancy. Doxycycline, the current standard therapy, must be taken twice daily for at least 7 days. Patient compliance is often poor, leading to recurrent disease. Azithromycin, a new antibiotic of the Azalide class, achieves high and sustained intracellular levels and demonstrates excellent in vitro activity against C. trachomatis . Reported herein are the results of three comparative clinical trials, which demonstrate that single-dose oral therapy with azithromycin is as effective as a standard 7-day twice-daily course of doxycycline in the treatment of uncomplicated genital infections caused by C. trachomatis .
James L Occi - One of the best experts on this subject based on the ideXlab platform.
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synthesis and antibacterial activity of o methyl derivatives of Azalide antibiotics ii 6 ome derivatives via clarithromycin
Bioorganic & Medicinal Chemistry Letters, 1998Co-Authors: Sherman T Waddell, Gina M Santorelli, Timothy A Blizzard, Amy C Graham, James L OcciAbstract:Abstract Direct O-methylation of various derivatives of 9-deoxo-8a- and 9a-aza-8a-homo-erythromycin (2′,3′-bis-Cbz protected) gives 6-OMe derivatives only in a small number of special cases. The 6-OMe-Azalides can, however, be synthesized beginning from clarithromycin.
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synthesis and antibacterial activity of o methyl derivatives of Azalide antibiotics i 4 11 and 12 ome derivatives via direct methylation
Bioorganic & Medicinal Chemistry Letters, 1998Co-Authors: Sherman T Waddell, Gina M Santorelli, Timothy A Blizzard, Amy C Graham, James L OcciAbstract:Abstract A series of O-Me derivatives of 9-deoxo-8a-aza-8a-homoerythromycin has been prepared and evaluated for antibacterial activity. The relative rates of methylation of the four available hydroxyls (4″, 6, 11 and 12) in 2′, 3′ -bis-Cbz protected 9-deoxo-8a-aza-8a-homoerythromycin were compared to those given in a published report for the similarly protected 9a-Azalide. An incongruity in the results prompted reinvestigation of the O-methylation of the 9a-Azalide, and an error in structure assignment in the published report was discovered: the compound reported as the 6-OMe-9a-Azalide has been determined to be the 12-OMe derivative.
Shigeru F Hayashi - One of the best experts on this subject based on the ideXlab platform.
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in vitro microbiological characterization of a novel Azalide two triamilides and an Azalide ketal against bovine and porcine respiratory pathogens
ChemInform, 2004Co-Authors: Laura J L Norcia, Kristin Marie Lundy, Sheryl L Santoro, Annette M Silvia, Jim Retsema, Michael A Letavic, Brian Scott Bronk, Bingwei Yang, Nigel A Evans, Shigeru F HayashiAbstract:Several novel 15-membered-ring macrolide agents (Azalide 1, triamilides 2 and 3, and the Azalide 3, 6-ketal 4) were identified as potential antibacterial agents against Mannheimia (formerly named as Pasteurella) haemolytica, Pasteurella multocida, Haemophilus somnus and Actinobacillus pleuropneumoniae, important etiological agents of bovine and porcine respiratory disease. Compound 3 is the major component of the antibiotic tulathromycin. Antibacterial activity against tilmicosin-resistant P. multocida field isolates was also tested. In vitro MIC 50/90 analysis revealed that the four newly synthesized compounds were more potent than tilmicosin against M. haemolytica (4-8×), P. multocida (8-16×), A. pleuropneumoniae (4×), H. somnus (2× and 16×), and tilmicosin-resistant P. multocida (32×). In time-kill kinetic studies, all four novel compounds and tilmicosin showed bactericidal activity against M. haemolytica, P. multocida and A. pleuropneumoniae at both 4× and 8× MIC. A functional assay using genetically defined mutants revealed that all four novel compounds were poorer substrates for the efflux pump, AcrA/B system, than tilmicosin. A pH study using LPS mutants indicated that the enhanced in vitro potency of the triamilides, particularly compound 3 was mainly due to better penetration of the molecule through the outer membrane. The third amine group at the C-4" position of the triamilde molecules contributed to this increased membrane penetration by increasing overall basicity. These studies indicate that the four novel compounds have potential as antibacterial agents against bovine and porcine respiratory disease.
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Azalide 3 6 ketals antibacterial activity and structure activity relationships of aryl and hetero aryl substituted analogues
Bioorganic & Medicinal Chemistry Letters, 2003Co-Authors: Subas M Sakya, Hengmiao Cheng, Carl B Ziegler, Kristin Marie Lundy, Barbara J Kamicker, Peter Bertinato, Bryan Pratt, Melani Suarezcontreras, Martha L Minich, Shigeru F HayashiAbstract:Aryl and hetero aryl substituted 3,6-ketals of 15-membered Azalide analogues were synthesized and were found to have potent in vitro antibacterial activity against veterinary pathogens, including Staphylococcus aureus and Pasteurella multocida.
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synthesis and sar of Azalide 3 6 ketal aromatic derivatives as potent gram positive and gram negative antibacterial agents
Bioorganic & Medicinal Chemistry Letters, 2002Co-Authors: Hengmiao Cheng, John P Dirlam, Carl B Ziegler, Kristin Marie Lundy, Shigeru F Hayashi, Barbara J Kamicker, Jason K Dutra, Kirsten L Daniel, Sheryl L Santoro, David M GeorgeAbstract:3,6-Ketals of 15-membered Azalide pseudoaglycones are a novel series of macrolide antibiotics. The aromatic derivatives of the Azalide 3,6-ketals demonstrated potent antibacterial activities against both Gram-positive and Gram-negative bacteria.
Thomas Hanemann - One of the best experts on this subject based on the ideXlab platform.
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mixtures of ionic liquid and sulfolane as electrolytes for li ion batteries
Electrochimica Acta, 2014Co-Authors: Andreas Hofmann, Sylvio Indris, M Schulz, Ralf Heinzmann, Thomas HanemannAbstract:Abstract In this study, novel temperature stable electrolyte mixtures are investigated with respect to their use in Li-ion cells. Sulfolane, 3-methylsulfolane, and the ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl) azanide (DMMA-TFSA) are chosen as main components in the electrolyte mixtures. The electrolytes are studied in cell tests with LiNi1/3Mn1/3Co1/3O2 (NMC) as cathode and graphite as anode material. The performance of the cells is tested at room temperature and at elevated temperatures (40 °C) which demonstrates the significant improvement of the cell performance by raising the temperature slightly. Furthermore, the additives vinylene carbonate and hexamethyldisilazane are used to improve the electrolyte properties with respect to cell performance and long term stability.
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anodic aluminum dissolution of litfsa containing electrolytes for li ion batteries
Electrochimica Acta, 2014Co-Authors: Andreas Hofmann, M Schulz, Lisa Merklein, Thomas HanemannAbstract:Abstract In this study, novel electrolyte solvents and the conducting salt lithium bis(trifluoromethanesulfonyl)azanide (LiTFSA) are compared with respect to aluminum anodic dissolution, often called in an ambiguous manner aluminum corrosion. Namely, mixtures of propylene carbonate, sulfolane, the ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)azanide (DMMA-TFSA) and various concentrations of LiTFSA are prepared and investigated in Al|Li cell configuration. It is verified that the choice of the concentration of LiTFSA and the composition of the solvent mixture affects the tendency of Al dissolution significantly. Principally, the best results (least dissolution/corrosion) are obtained in case of high LiTFSA concentrations and by adding the ionic liquid DMMA-TFSA to the organic solvents.
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suppressed lithium dendrite growth in lithium batteries using ionic liquid electrolytes investigation by electrochemical impedance spectroscopy scanning electron microscopy and in situ 7li nuclear magnetic resonance spectroscopy
Journal of Power Sources, 2013Co-Authors: Nina Schweikert, Marco Scheuermann, Steven T Boles, Horst Hahn, Thomas Hanemann, Andreas Hofmann, Michael Schulz, Sylvio IndrisAbstract:Abstract In this work, the formation of lithium dendrites in lithium/Li4Ti5O12 battery cells is studied using different experimental techniques. Electrochemical impedance spectroscopy is presented as a tool to investigate non-invasively the dendritic growth on a lithium metal surface in lithium/Li4Ti5O12 cells during numerous discharging/charging cycles. Scanning electron microscopy is used for visual inspection of the dendrite formation. In situ 7Li nuclear magnetic resonance spectroscopy is sensitive to quantitative changes at the lithium metal surface. Application to symmetrical lithium/lithium battery cells allows for a careful comparison of the investigated electrolytes. All these experimental methods provide consistent results. It is demonstrated that the growth of lithium dendrites is significantly correlated to the electrolyte employed. All electrolytes based on the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)azanide (EMIM-TFSA) show reduced dendrite growth in comparison to the standard electrolyte for Li-ion batteries, lithium hexafluorophosphate (LiPF6) in ethylene carbonate/dimethyl carbonate (EC/DMC). LiPF6 in EMIM-TFSA and LiPF6 in EMIM-TFSA/propylene carbonate suppress lithium dendrites most efficiently.
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gel electrolytes based on ionic liquids for advanced lithium polymer batteries
Electrochimica Acta, 2013Co-Authors: Andreas Hofmann, M Schulz, Thomas HanemannAbstract:Abstract A new ionic liquid-based polymer gel electrolyte for lithium ion batteries is prepared by combining N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)azanide, organic carbonates, lithium bis(trifluoromethylsulfonyl)azanide, and poly(vinylidene fluoride-co-hexafluoropropylene). The conductivities of the gel electrolytes at room temperature are about 1–2 mS/cm. It is shown that the polymer gel electrolytes work effectively with a graphite anode and a LiCo 1/3 Mn 1/3 Ni 1/3 O 2 cathode. Further it is proven that the addition of vinylene carbonate and 4-vinylpyridine considerably improves the cell performance.
