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Development of Novel Membrane Disrupting Lipoguanidine Compounds Sensitizing Gram-Negative Bacteria to Antibiotics. ACS Med Chem Lett 2024; 15:239-249. [PMID: 38352828 PMCID: PMC10860194 DOI: 10.1021/acsmedchemlett.3c00460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/20/2023] [Accepted: 01/02/2024] [Indexed: 02/16/2024] Open
Abstract
A new class of amphiphilic molecules, the lipoguanidines, designed as hybrids of guanidine and fatty acid compounds, has been synthesized and developed. The new molecules present both a guanidine polar head and a lipophilic tail that allow them to disrupt bacterial membranes and to sensitize Gram-negative bacteria to the action of the narrow-spectrum antibiotics rifampicin and novobiocin. The lipoguanidine 5g sensitizes Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli to rifampicin, thereby reducing the antibiotic minimum inhibitory concentrations (MIC) up to 256-fold. Similarly, 5g is able to potentiate novobiocin up to 64-fold, thereby showing a broad spectrum of antibiotic potentiating activity. Toxicity and mechanism studies revealed the potential of 5g to work synergistically with rifampicin through the disruption of bacterial membranes without affecting eukaryotic cells.
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Synergy between Winter Flounder antimicrobial peptides. NPJ ANTIMICROBIALS AND RESISTANCE 2023; 1:8. [PMID: 38686212 PMCID: PMC11057203 DOI: 10.1038/s44259-023-00010-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/23/2023] [Indexed: 05/02/2024]
Abstract
Some antimicrobial peptides (AMPs) have potent bactericidal activity and are being considered as potential alternatives to classical antibiotics. In response to an infection, such AMPs are often produced in animals alongside other peptides with low or no perceivable antimicrobial activity, whose role is unclear. Here we show that six AMPs from the Winter Flounder (WF) act in synergy against a range of bacterial pathogens and provide mechanistic insights into how this increases the cooperativity of the dose-dependent bactericidal activity and potency that enable therapy. Only two WF AMPs have potent antimicrobial activity when used alone but we find a series of two-way combinations, involving peptides which otherwise have low or no activity, yield potent antimicrobial activity. Weakly active WF AMPs modulate the membrane interactions of the more potent WF AMPs and enable therapy in a model of Acinetobacter baumannii burn wound infection. The observed synergy and emergent behaviour may explain the evolutionary benefits of producing a family of related peptides and are attractive properties to consider when developing AMPs towards clinical applications.
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Adamantane appended antimicrobial supramolecular self-associating amphiphiles. Supramol Chem 2023. [DOI: 10.1080/10610278.2022.2161902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
MGB-BP-3 is a potential first-in-class antibiotic, a Strathclyde Minor Groove Binder (S-MGB), that has successfully completed Phase IIa clinical trials for the treatment of Clostridioides difficile associated disease. Its precise mechanism of action and the origin of limited activity against Gram-negative pathogens are relatively unknown. Herein, treatment with MGB-BP-3 alone significantly inhibited the bacterial growth of the Gram-positive, but not Gram-negative, bacteria as expected. Synergy assays revealed that inefficient intracellular accumulation, through both permeation and efflux, is the likely reason for lack of Gram-negative activity. MGB-BP-3 has strong interactions with its intracellular target, DNA, in both Gram-negative and Gram-positive bacteria, revealed through ultraviolet-visible (UV-vis) thermal melting and fluorescence intercalator displacement assays. MGB-BP-3 was confirmed to bind to dsDNA as a dimer using nano-electrospray ionization mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. Type II bacterial topoisomerase inhibition assays revealed that MGB-BP-3 was able to interfere with the supercoiling action of gyrase and the relaxation and decatenation actions of topoisomerase IV of both Staphylococcus aureus and Escherichia coli. However, no evidence of stabilization of the cleavage complexes was observed, such as for fluoroquinolones, confirmed by a lack of induction of DSBs and the SOS response in E. coli reporter strains. These results highlight additional mechanisms of action of MGB-BP-3, including interference of the action of type II bacterial topoisomerases. While MGB-BP-3's lack of Gram-negative activity was confirmed, and an understanding of this presented, the recognition that MGB-BP-3 can target DNA of Gram-negative organisms will enable further iterations of design to achieve a Gram-negative active S-MGB.
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Bactericidal Effect of Ultrasound-Responsive Microbubbles and Sub-inhibitory Gentamicin against Pseudomonas aeruginosa Biofilms on Substrates With Differing Acoustic Impedance. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:1888-1898. [PMID: 35798625 DOI: 10.1016/j.ultrasmedbio.2022.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
The aim of this research was to explore the interaction between ultrasound-activated microbubbles (MBs) and Pseudomonas aeruginosa biofilms, specifically the effects of MB concentration, ultrasound exposure and substrate properties on bactericidal efficacy. Biofilms were grown using a Centre for Disease Control (CDC) bioreactor on polypropylene or stainless-steel coupons as acoustic analogues for soft and hard tissue, respectively. Biofilms were treated with different concentrations of phospholipid-shelled MBs (107-108 MB/mL), a sub-inhibitory concentration of gentamicin (4 µg/mL) and 1-MHz ultrasound with a continuous or pulsed (100-kHz pulse repetition frequency, 25% duty cycle, 0.5-MPa peak-to-peak pressure) wave. The effect of repeated ultrasound exposure with intervals of either 15- or 60-min was also investigated. With polypropylene coupons, the greatest bactericidal effect was achieved with 2 × 5 min of pulsed ultrasound separated by 60 min and a microbubble concentration of 5 × 107 MBs/mL. A 0.76 log (83%) additional reduction in the number of bacteria was achieved compared with the use of an antibiotic alone. With stainless-steel coupons, a 67% (0.46 log) reduction was obtained under the same exposure conditions, possibly due to enhancement of a standing wave field which inhibited MB penetration in the biofilm. These findings demonstrate the importance of treatment parameter selection in antimicrobial applications of MBs and ultrasound in different tissue environments.
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AB1583-PARE QUALITATIVE INTERVIEWS OF SYMPTOMS, IMPACTS AND SELECTED PROMIS SHORT FORMS: A STUDY IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.2368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundAxial spondyloarthritis (axSpA) is characterised by inflammation of the sacroiliac joints and spine. Sleep disturbance, pain and fatigue are reported in the literature to be key symptoms and impacts of axSpA. Three customised Patient-Reported Outcomes Measurement Information System (PROMIS) Short Forms (Sleep Disturbance, Pain Interference and Fatigue), previously developed for use in rheumatoid arthritis, have been proposed for use in patients with axSpA to assess the key concepts.ObjectivesTo conduct in-depth qualitative interviews to further understand the patient experience of axSpA and evaluate the content validity of the three PROMIS Short Forms to support their use as endpoints in axSpA clinical trials.MethodsA non-interventional, cross-sectional qualitative (concept elicitation [CE] and cognitive debriefing [CD]) study was conducted in 28 adult patients with diagnosed axSpA, including radiographic axSpA (r-axSpA), also known as ankylosing spondylitis (AS, n=12), and non-radiographic axSpA (nr-axSpA, n=16). Patients took part in 90-minute telephone interviews. A semi-structured interview guide was used to assist discussions. The CE section used broad, open-ended questions to elicit information about symptoms and impact experienced by patients. The CD section involved a ‘think-aloud’ exercise in which patients read out each instruction, item and response option for the three PROMIS Short Forms and shared their feedback. Patients were also asked detailed questions about the relevance of the items, response options and recall period. Verbatim interview transcripts were subject to thematic and content analysis.ResultsPatients were from the United States (n=20) and Germany (n=8), mean age was 52.8 years, and 57% (n=16) were male; mean time since diagnosis of axSpA was 9.5 years (range 0.3–31.3 years). The CE section identified 12 distinct signs and symptoms that characterised patients’ experience of axSpA: pain, sleep problems, fatigue/tiredness, stiffness, swelling, vision/eye issues, restricted body movements, headache/migraine, spasms, change in posture/stature, balance/coordination problems and numbness. Pain, sleep problems and fatigue/tiredness were all reported to be experienced by ≥90% of patients, occurring simultaneously and exacerbating one another. 78% (n=21/27) of patients reported pain to be the most bothersome symptom, and 88% (n=23/26) described it as the symptom they would most like treatment to improve. Patients reported axSpA to impact their lives across six health-related quality of life (HRQoL) domains: physical functioning (100%), emotional wellbeing (89%), work/volunteering (79%), social functioning (75%), activities of daily living (61%) and cognitive functioning (54%). Impacts were most frequently described as being associated with pain, stiffness and fatigue. The experiences of symptoms and impacts were consistent between the AS and nr-axSpA patients. CD showed all three PROMIS instruments are conceptually comprehensive and well understood by patients with axSpA. No patients reported misunderstanding of instructions and/or items of the sleep disturbance instrument, and only one and four items had a small number of instances of misunderstanding for the fatigue and pain interference instruments, respectively. Across each instrument, all items were relevant to at least half of patients, and almost all patients reported the instruments to be appropriate for measuring their experience of sleep problems, pain and fatigue due to axSpA. Both AS and nr-axSpA patients confirmed the three PROMIS Short Forms to be relevant and appropriate for assessing their disease experience.ConclusionPain, sleep problems and fatigue are pivotal symptoms of axSpA and associated with HRQoL impacts. Interpretability and content validity of the PROMIS customised Short Forms have been confirmed, with each deemed to adequately assess key impacts associated with axSpA, making them suitable for use in clinical trials of patients with axSpA.Funding: GSK [209770]AcknowledgementsMedical writing support was provided by Tony Reardon, of of Aura, a division of Spirit Medical Communications Group Limited (Manchester, UK), and was funded by GlaxoSmithKline.Disclosure of InterestsAmy Findley Grant/research support from: employee of Adelphi Values, who received fees from GlaxoSmithKline for the conduct of this study, Jessica Middlehurst Grant/research support from: employee of Adelphi Values, who received fees from GlaxoSmithKline for the conduct of this study, Chloe Howse Grant/research support from: employee of Adelphi Values, who received fees from GlaxoSmithKline for the conduct of this study, Molly Clifford Grant/research support from: employee of Adelphi Values, who received fees from GlaxoSmithKline for the conduct of this study, William Neill Grant/research support from: employee of Adelphi Values, who received fees from GlaxoSmithKline for the conduct of this study, Sophi Tatlock Grant/research support from: employee of Adelphi Values, who received fees from GlaxoSmithKline for the conduct of this study, Wen-Hung Chen Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline, Marguerite Bracher Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline, Dharm Patel Shareholder of: GlaxoSmithKline, Employee of: GlaxoSmithKline
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Temporin B Forms Hetero-Oligomers with Temporin L, Modifies Its Membrane Activity, and Increases the Cooperativity of Its Antibacterial Pharmacodynamic Profile. Biochemistry 2022; 61:1029-1040. [PMID: 35609188 PMCID: PMC9178791 DOI: 10.1021/acs.biochem.1c00762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The pharmacodynamic
profile of antimicrobial peptides (AMPs) and
their in vivo synergy are two factors that are thought
to restrict resistance evolution and ensure their conservation. The
frog Rana temporaria secretes a family of closely
related AMPs, temporins A–L, as an effective chemical dermal
defense. The antibacterial potency of temporin L has been shown to
increase synergistically in combination with both temporins B and
A, but this is modest. Here we show that the less potent temporin
B enhances the cooperativity of the in vitro antibacterial
activity of the more potent temporin L against EMRSA-15 and that this
may be associated with an altered interaction with the bacterial plasma
membrane, a feature critical for the antibacterial activity of most
AMPs. Addition of buforin II, a histone H2A fragment, can further
increase the cooperativity. Molecular dynamics simulations indicate
temporins B and L readily form hetero-oligomers in models of Gram-positive
bacterial plasma membranes. Patch-clamp studies show transmembrane
ion conductance is triggered with lower amounts of both peptides and
more quickly when used in combination, but conductance is of a lower
amplitude and pores are smaller. Temporin B may therefore act by forming
temporin L/B hetero-oligomers that are more effective than temporin
L homo-oligomers at bacterial killing and/or by reducing the probability
of the latter forming until a threshold concentration is reached.
Exploration of the mechanism of synergy between AMPs isolated from
the same organism may therefore yield antibiotic combinations with
advantageous pharmacodynamic properties.
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Di-anionic self-associating supramolecular amphiphiles (SSAs) as antimicrobial agents against MRSA and Escherichia coli. Chem Commun (Camb) 2021; 57:11839-11842. [PMID: 34698738 DOI: 10.1039/d1cc05455d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we report a series of di-anionic supramolecular self-associating amphiphiles (SSAs). We elucidate the antimicrobial properties of these SSAs against both methicillin resistant Staphylococcus aureus and Escherichia coli. In addition, we show this class of compound to form both intra- and intermolecular hydrogen bonded macrocyclic structures in the solid state.
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Synthesis, microbiological evaluation and structure activity relationship analysis of linezolid analogues with different C5-acylamino substituents. Bioorg Med Chem 2021; 49:116397. [PMID: 34619406 DOI: 10.1016/j.bmc.2021.116397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/29/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
Antimicrobial resistance and lack of new antibiotics to treat multidrug-resistant (MDR) bacteria is a significant public health problem. There is a discovery void and the pipeline of new classes of antibiotics in clinical development is almost empty. Therefore, it is important to understand the structure activity relationships (SAR) of current chemical classes as that can help the drug discovery community in their efforts to develop new antibiotics by modifying existing antibiotic classes. We studied the SAR of the C5-acylaminomethyl moiety of the linezolid, an oxazolidinone antibiotic, by synthesizing 25 compounds containing various aromatic, heteroaromatic and aliphatic substitutions. Our findings suggest that this position is highly important for the function of this antibiotic class, since only smaller non-polar fragments are tolerated at this position while larger and polar ones lead to a decrease in activity compared to linezolid. Our findings have led us to construct a structure activity relationship, around the C5-acylaminomethyl moiety of linezolid, that provides valuable insight into the function of the oxazolidinone class of antibiotics.
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Schiff bases of sulphonamides as a new class of antifungal agent against multidrug-resistant Candida auris. Microbiologyopen 2021; 10:e1218. [PMID: 34459551 PMCID: PMC8301596 DOI: 10.1002/mbo3.1218] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/10/2021] [Accepted: 06/24/2021] [Indexed: 11/11/2022] Open
Abstract
Invasive Candida infections in hospitalized and immunocompromised or critically ill patients have become an important cause of morbidity and mortality. There are increasing reports of multidrug resistance in several Candida species that cause Candidemia, including C. glabrata and C. auris, with limited numbers of antifungal agents available to treat patients with invasive Candida infections. Therefore, there is an urgent need to discover new antifungal agents that work against multidrug-resistant Candida species, particularly C. auris, which has been identified as an emerging global pathogen. In this article, we report a new class of antifungal agents, the Schiff bases of sulphonamides, that show activity against all Candida species tested, with an MIC range of 4-32 µg/ml. Compound 2b showed activity against C. glabrata and a panel of fluconazole-resistant C. auris strains, with MICs of 4-16 µg/ml. The drug-like nature of these Schiff bases offers opportunities to optimize these compounds with medicinal chemistry techniques to obtain more potent analogs that can be progressed toward pre-clinical evaluation.
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Development of photoactivable phenanthroline-based manganese(I) CO-Releasing molecules (PhotoCORMs) active against ESKAPE bacteria and bacterial biofilms. Eur J Med Chem 2021; 213:113172. [PMID: 33516984 DOI: 10.1016/j.ejmech.2021.113172] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/02/2023]
Abstract
The synthesis and biological evaluation of a series of phenanthroline-based visible-light-activated manganese(I) carbon-monoxide-releasing molecules (PhotoCORMs) against ESKAPE bacteria and bacterial biofilms is reported. Four carbonyl compounds of general formula fac-[Mn(N∧N)(CO)3(L)] have been synthesized and characterized. Despite being thermally stable in the absence of light, these PhotoCORMs readily release CO upon blue (435-450 nm) LED light irradiation as confirmed by spectrophotometric CO releasing experiments (Mb Assay). The antibacterial activity of the four PhotoCORMs has been investigated against a panel of ESKAPE bacteria. The compounds 1-3 were found to be effective antibacterials at low concentrations against multidrug-resistant Klebsiella pneumoniae and Acinetobacter baumannii when photoactivated with blue-light. In addition, the PhotoCORMs 1-2 were found to inhibit the formation of Klebsiella pneumoniae and Acinetobacter baumannii bacterial biofilms at low concentrations (MIC = 4-8 μg/mL), turning out to be promising candidates to combat antimicrobial resistance. The antibacterial and biofilm inhibitory effect of the PhotoCORMs is plausibly due to the release of CO as well as the formation of phenanthroline photo-by-products as revealed by spectroscopy and microbiology experiments.
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A pleurocidin analogue with greater conformational flexibility, enhanced antimicrobial potency and in vivo therapeutic efficacy. Commun Biol 2020; 3:697. [PMID: 33247193 PMCID: PMC7699649 DOI: 10.1038/s42003-020-01420-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 10/22/2020] [Indexed: 01/08/2023] Open
Abstract
Antimicrobial peptides (AMPs) are a potential alternative to classical antibiotics that are yet to achieve a therapeutic breakthrough for treatment of systemic infections. The antibacterial potency of pleurocidin, an AMP from Winter Flounder, is linked to its ability to cross bacterial plasma membranes and seek intracellular targets while also causing membrane damage. Here we describe modification strategies that generate pleurocidin analogues with substantially improved, broad spectrum, antibacterial properties, which are effective in murine models of bacterial lung infection. Increasing peptide-lipid intermolecular hydrogen bonding capabilities enhances conformational flexibility, associated with membrane translocation, but also membrane damage and potency, most notably against Gram-positive bacteria. This negates their ability to metabolically adapt to the AMP threat. An analogue comprising D-amino acids was well tolerated at an intravenous dose of 15 mg/kg and similarly effective as vancomycin in reducing EMRSA-15 lung CFU. This highlights the therapeutic potential of systemically delivered, bactericidal AMPs.
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N1-Benzofused Modification of Fluoroquinolones Reduces Activity Against Gram-Negative Bacteria. ACS OMEGA 2020; 5:11923-11934. [PMID: 32548371 PMCID: PMC7271024 DOI: 10.1021/acsomega.9b03910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/10/2020] [Indexed: 06/11/2023]
Abstract
The fluoroquinolone class of antibiotics has a well-established structure-activity relationship (SAR) and a long history in the clinic, but the effect of electron-rich benzofused substituents at the N1 position remains poorly explored. Because groups at this position are part of the topoisomerase-DNA binding complex and form a hydrophobic interaction with the major groove of DNA, it was hypothesized that an electron-rich benzofused N1 substituent could enhance this interaction. Molecular modeling techniques were employed to evaluate the binding of certain N1-modified fluoroquinolones to DNA gyrase targets from both Staphylococcus aureus and Klebsiella pneumoniae species compared with ciprofloxacin and norfloxacin. Seven N1-modified fluoroquinolones were subsequently synthesized and tested against a panel of Gram-negative pathogens to determine minimum inhibitory concentration (MIC) values. Gram-negative outer membrane penetration was investigated using the membrane permeabilizer polymyxin B nonapeptide and compound efflux via resistance-nodulation-division-family efflux transporters was evaluated using the known efflux pump inhibitor phenylalanine-arginine β-naphthylamide. Additionally, the target inhibitory activity of representative compound 6e was determined in a cell-free environment. A correlation between N1 substituent hydrophobicity and activity was observed across the MIC panel, with compound activity decreasing with increased hydrophobicity. Those compounds with highest hydrophobicity were inactive because of poor solubility profiles whereas compounds with intermediate hydrophobicity were inactive because of impaired outer membrane penetration, and reduced inhibition of topoisomerase targets, the latter in contrast to modeling predictions. This study adds new information to the fluoroquinolone SAR and suggests limited utility of large hydrophobic substituents at the N1 position of fluoroquinolones.
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Synthetic Antimicrobial Peptide Tuning Permits Membrane Disruption and Interpeptide Synergy. ACS Pharmacol Transl Sci 2020; 3:418-424. [PMID: 32566907 DOI: 10.1021/acsptsci.0c00001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Indexed: 12/19/2022]
Abstract
The ribosomally produced antimicrobial peptides of bacteria (bacteriocins) represent an unexplored source of membrane-active antibiotics. We designed a library of linear peptides from a circular bacteriocin and show that pore-formation dynamics in bacterial membranes are tunable via selective amino acid substitution. We observed antibacterial interpeptide synergy indicating that fundamentally altering interactions with the membrane enables synergy. Our findings suggest an approach for engineering pore-formation through rational peptide design and increasing the utility of novel antimicrobial peptides by exploiting synergy.
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Switching on the activity of 1,5-diaryl-pyrrole derivatives against drug-resistant ESKAPE bacteria: Structure-activity relationships and mode of action studies. Eur J Med Chem 2019; 178:500-514. [DOI: 10.1016/j.ejmech.2019.05.087] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022]
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Minor sequence modifications in temporin B cause drastic changes in antibacterial potency and selectivity by fundamentally altering membrane activity. Sci Rep 2019; 9:1385. [PMID: 30718667 PMCID: PMC6362004 DOI: 10.1038/s41598-018-37630-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 12/10/2018] [Indexed: 11/08/2022] Open
Abstract
Antimicrobial peptides (AMPs) are a potential source of new molecules to counter the increase in antimicrobial resistant infections but a better understanding of their properties is required to understand their native function and for effective translation as therapeutics. Details of the mechanism of their interaction with the bacterial plasma membrane are desired since damage or penetration of this structure is considered essential for AMPs activity. Relatively modest modifications to AMPs primary sequence can induce substantial changes in potency and/or spectrum of activity but, hitherto, have not been predicted to substantially alter the mechanism of interaction with the bacterial plasma membrane. Here we use a combination of molecular dynamics simulations, circular dichroism, solid-state NMR and patch clamp to investigate the extent to which temporin B and its analogues can be distinguished both in vitro and in silico on the basis of their interactions with model membranes. Enhancing the hydrophobicity of the N-terminus and cationicity of the C-terminus in temporin B improves its membrane activity and potency against both Gram-negative and Gram-positive bacteria. In contrast, enhancing the cationicity of the N-terminus abrogates its ability to trigger channel conductance and renders it ineffective against Gram-positive bacteria while nevertheless enhancing its potency against Escherichia coli. Our findings suggest even closely related AMPs may target the same bacterium with fundamentally differing mechanisms of action.
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Tracheal tube insertion is an essential part of modern paediatric anaesthesia and critical care: let us get it right. Br J Anaesth 2018; 116:582-4. [PMID: 27106959 DOI: 10.1093/bja/aew103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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C8-Linked Pyrrolobenzodiazepine Monomers with Inverted Building Blocks Show Selective Activity against Multidrug Resistant Gram-Positive Bacteria. ACS Infect Dis 2018; 4:158-174. [PMID: 29260545 DOI: 10.1021/acsinfecdis.7b00130] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Antimicrobial resistance has become a major global concern. Development of novel antimicrobial agents for the treatment of infections caused by multidrug resistant (MDR) pathogens is an urgent priority. Pyrrolobenzodiazepines (PBDs) are a promising class of antibacterial agents initially discovered and isolated from natural sources. Recently, C8-linked PBD biaryl conjugates have been shown to be active against some MDR Gram-positive strains. To explore the role of building block orientations on antibacterial activity and obtain structure activity relationship (SAR) information, four novel structures were synthesized in which the building blocks of previously reported compounds were inverted, and their antibacterial activity was studied. The compounds showed minimum inhibitory concentrations (MICs) in the range of 0.125-32 μg/mL against MDR Gram-positive strains with a bactericidal mode of action. The results showed that a single inversion of amide bonds reduces the activity while the double inversion restores the activity against MDR pathogens. All inverted compounds did not stabilize DNA and lacked eukaryotic toxicity. The compounds inhibit DNA gyrase in vitro, and the most potent compound was equally active against both wild-type and mutant DNA gyrase in a biochemical assay. The observed activity of the compounds against methicillin resistant S. aureus (MRSA) strains with equivalent gyrase mutations is consistent with gyrase inhibition being the mechanism of action in vivo, although this has not been definitively confirmed in whole cells. This conclusion is supported by a molecular modeling study showing interaction of the compounds with wild-type and mutant gyrases. This study provides important SAR information about this new class of antibacterial agents.
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Evaluation of Novel Process Indicators for Rapid Monitoring of Hydrogen Peroxide Decontamination Processes. PDA J Pharm Sci Technol 2017; 71:393-404. [PMID: 28512177 DOI: 10.5731/pdajpst.2016.007435] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Geobacillus stearothermophilus spores on stainless steel discs are routinely used as biological indicators for the validation of hydrogen peroxide bio-decontamination processes. Given ongoing concerns about the reliability and response time of biological indicators, we explored the potential for an enzyme-based approach to decontamination process evaluation. Thermostable adenylate kinase enzyme was coated onto a solid support and exposed to hydrogen peroxide vapour, in parallel with standard commercial 6-log biological indicators, during a series of vapour-phase hydrogen peroxide cycles in a flexible film isolator. The exposed biological indicators were enumerated to define the degree of kill at different time intervals and the results compared to the thermostable adenylate kinase values, as determined by measuring adenosine triphosphate produced by residual active enzyme. Both biological indicators and the thermostable adenylate kinase indicators exhibited a biphasic inactivation profile during the process. There was significant variance between individual cycles, with some cycles showing complete inactivation of the biological indicators to the limit of detection of the assay, within 6 min, whereas biological indicators in some cycles were inactivated at a time greater than 12 min. The log-kill of the biological indicators at intermediate time points were plotted and compared to the fully quantifiable measurements derived from the thermostable adenylate kinase indicators at the same time points. The results demonstrated very similar inactivation profiles for the enzyme and for the biological indicators, thus it was possible to define a relationship between relative light units measurement and biological indicator kill. This indicates that it is possible to use thermostable adenylate kinase measurement as a direct measure of vapour-phase hydrogen peroxide bio-decontamination performance, expressed in terms of log reduction. Because thermostable adenylate kinase measurement can be achieved within a few minutes of vapour-phase hydrogen peroxide cycle completion, compared with a minimum of 7 days for the evaluation of biological indicator growth, this offers a potentially valuable tool for rapid vapour-phase hydrogen peroxide bio-decontamination cycle development and subsequent re-qualification.LAY ABSTRACT: Pharmaceutical product manufacture is performed in controlled cleanroom and closed chamber environments (isolators) to reduce the risk of contamination. These environments undergo regular decontamination to control microbial contamination levels, using a range of methods, one of which is to vaporize hydrogen peroxide (a chemical disinfectant) into a gas or an aerosol and disperse it throughout the environment, killing any microorganisms present. Biological indicators, which consist of a small steel coupon carrying a population of bacterial spores that are more resistant to hydrogen peroxide than are most microorganisms, are placed within the environment, and then tested for growth following treatment to ensure the process was effective. Confirmation of growth/no growth (and therefore hydrogen peroxide cycle efficacy) can take up to 7 days, which significantly increases time and cost of developing and confirming cycle efficacy. This study tests whether a new technology which uses a robust enzyme, thermostable adenylate kinase, could be used to predict biological indicator growth. The study shows this method can be used to confirm hydrogen peroxide cycle efficacy, by predicting whether the BI is killed at a specific time point or not and results are obtained in a few minutes rather than 7 days. This potentially offers significant time and cost benefits.
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Triaryl Benzimidazoles as a New Class of Antibacterial Agents against Resistant Pathogenic Microorganisms. J Med Chem 2017. [PMID: 28650661 DOI: 10.1021/acs.jmedchem.7b00108] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A new class of nontoxic triaryl benzimidazole compounds, derived from existing classes of DNA minor groove binders, were designed, synthesized, and evaluated for their antibacterial activity against multidrug resistant (MDR) Gram-positive and Gram-negative species. Molecular modeling experiments suggest that the newly synthesized class cannot be accommodated within the minor groove of DNA due to a change in the shape of the molecules. Compounds 8, 13, and 14 were found to be the most active of the series, with MICs in the range of 0.5-4 μg/mL against the MDR Staphylococci and Enterococci species. Compound 13 showed moderate activity against the MDR Gram-negative strains, with MICs in the range of 16-32 μg/mL. Active compounds showed a bactericidal mode of action, and a mechanistic study suggested the inhibition of bacterial gyrase as the mechanism of action (MOA) of this chemical class. The MOA was further supported by the molecular modeling study.
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Intellectual abilities in tuberous sclerosis complex: risk factors and correlates from the Tuberous Sclerosis 2000 Study. Psychol Med 2015; 45:2321-2331. [PMID: 25827976 DOI: 10.1017/s0033291715000264] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is associated with intellectual disability, but the risk pathways are poorly understood. METHOD The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of the natural history of TSC. One hundred and twenty-five UK children age 0-16 years with TSC and born between January 2001 and December 2006 were studied. Intelligence was assessed using standardized measures at ≥2 years of age. The age of onset of epilepsy, the type of seizure disorder, the frequency and duration of seizures, as well as the response to treatment was assessed at interview and by review of medical records. The severity of epilepsy in the early years was estimated using the E-Chess score. Genetic studies identified the mutations and the number of cortical tubers was determined from brain scans. RESULTS TSC2 mutations were associated with significantly higher cortical tuber count than TSC1 mutations. The extent of brain involvement, as indexed by cortical tuber count, was associated with an earlier age of onset and severity of epilepsy. In turn, the severity of epilepsy was strongly associated with the degree of intellectual impairment. Structural equation modelling supported a causal pathway from genetic abnormality to cortical tuber count to epilepsy severity to intellectual outcome. Infantile spasms and status epilepticus were important contributors to seizure severity. CONCLUSIONS The findings support the proposition that severe, early onset epilepsy may impair intellectual development in TSC and highlight the potential importance of early, prompt and effective treatment or prevention of epilepsy in tuberous sclerosis.
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Validation of the VitalPACTM early warning score (ViEWS) in acutely ill medical patients admitted. IRISH MEDICAL JOURNAL 2013; 106:318. [PMID: 24579416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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How does the introduction of a pain and sedation management guideline in the paediatric intensive care impact on clinical practice? A comparison of audits pre and post guideline introduction. Aust Crit Care 2013. [DOI: 10.1016/j.aucc.2013.02.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Performance of TOTAL, in medical patients attending a resource-poor hospital in sub-Saharan Africa and a small Irish rural hospital. Acute Med 2013; 12:135-140. [PMID: 24098872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Recently a very simple, easy to remember early warning score (EWS) dubbed TOTAL has been reported. The score was derived from 309 acutely ill medical patients admitted to a Malawian hospital and awards one point for Tachypnea >30 breaths per minute, one point for Oxygen saturation <90%, two points for a Temperature <35°C, one point for Altered mental status, and one point for Loss of independence as indicated by the inability to stand or walk without help. TOTAL has an area under the receiver operator characteristic curve (AUROC) for death within 72 hours of 78%. METHODS We compared the performance of the TOTAL score in 849 medical patients attending a resource poor hospital in Uganda and 2935 patients admitted to a small rural hospital in Ireland. RESULTS TOTAL's AUROC for death within 24 hours was the same in both hospital populations: 85.1% (95% CI 78.6 - 91.6%) for Kitovu Hospital patients and 84.7% (95% CI 77.1 - 92.2%) for Nenagh Hospital patients. CONCLUSION The discrimination of TOTAL is exactly the same in elderly Irish patients as it is in young African patients. The score is easy to remember, easy to calculate, and works over a broad range of patients.
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Feasibility of percutaneous transabdominal portosystemic shunt creation. Surg Radiol Anat 2002; 24:217-21. [PMID: 12375077 DOI: 10.1007/s00276-002-0040-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2001] [Accepted: 02/01/2002] [Indexed: 10/27/2022]
Abstract
Evaluation of the anatomic feasibility of the percutaneous transabdominal puncture of selected portal and hepatic veins in patients with cirrhosis was performed. This approach would become the framework for an image-guided robot-assisted needle drive mechanism for use in transjugular intrahepatic portosystemic shunt (TIPS) creation. Retrospective analysis of 10 CT and 14 MRI axial abdominal studies was carried out to determine whether single simultaneous transabdominal puncture of portal and hepatic veins was possible. A necessary modification of the TIPS procedure was tested in an ex vivo porcine model under fluoroscopy. Eighteen of 24 patients (75%) had intrahepatic vascular anatomy amenable to a single transabdominal puncture. Successful catheterization of portal and hepatic veins using a modified approach for TIPS was accomplished in two ex vivo porcine livers. A suitable anatomic approach for modified TIPS is present in a majority of patients with cirrhosis. Feasibility of the technique using this anatomic approach was confirmed in two ex vivo porcine models. This study serves as an initial step in a novel technical approach to TIPS using a new anatomic approach for this procedure.
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Abstract
The effectiveness of conventional solid tumor treatment is limited by the systemic toxicity and lack of specificity of chemotherapeutic agents. Present treatment modalities are frequently insufficient to eliminate competent cancer cells without exceeding the limits of toxicity to normal tissue. The coming generation of cancer therapeutics depends on the precise targeting and sustained release of antitumor agents to overcome these limitations. We are developing an image-guided, robotic system for precise intratumoral placement of anticancer drugs and sustained release devices to advance this new treatment paradigm. The robotic system will use intraoperatively obtained computed tomographic (CT) images from a mobile CT scanner for guidance. The concept is to track patient anatomy and localize instruments using currently available optical tracking technology. Tracking will also be used to register patient anatomy with the images. The physician can then use the registered image to select an appropriate tumor target and entry location and to plan the instrument path. This path will then be transmitted to the robot, which orients and drives the instrument to the desired target under physician control. Achievement of the target is confirmed via intraoperative CT. This system will provide instrument guidance that is precise, direct, and controllable. Error due to poor target visualization and hand unsteadiness should be reduced greatly. The basic components of the system (robot, mobile CT, tracking) have been demonstrated in our laboratory, and the integration of the components is in progress. In future work, we plan to fuse preoperative PET imaging with intraoperative CT to allow functional as well as anatomic image guidance.
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Inhibition of 1,2-dimethylhydrazine-induced oxidative DNA damage in rat colon mucosa by black tea complex polyphenols. Food Chem Toxicol 2000; 38:1085-8. [PMID: 11033196 DOI: 10.1016/s0278-6915(00)00109-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The effect of black tea polyphenols on 1,2-dimethylhydrazine (DMH)-induced oxidative DNA damage in rat colon mucosa has been investigated. Fischer 344 rats were treated orally with thearubigin (TR) or theafulvin (TFu) for 10 days (40 mg/kg), injected ip with DMH (20 mg/kg) or saline and sacrificed 24 hr after DMH administration. The levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured in colonic mucosa DNA and expressed as a ratio relative to 2'-deoxyguanosine (2dG). Control rat mucosa had 8-OHdG values of 1.12 +/- 0.14/10(5) dG (mean +/- SEM, n=11), whereas DMH-treated rats significantly higher values (1.52 +/- 0.14/10(5) dG, n=26, P<0.05). Pretreatment of rats with TR had significantly inhibited DMH-induced oxidative DNA damage 0.99 +/- 0.09/10(5) dG, n=10, P<0.05) and a similar, although less marked, effect was observed with TFu (1.15 +/- 0.19/10(5), n=9, P=0.06). These findings confirm that DMH causes oxidative DNA damage in the colon mucosa of rats and demonstrate that this effect is prevented by the consumption of complex polyphenols from black tea.
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Technical Requirements for Image-guided Spinal Procedures: workshop report on intraprocedural imaging and endoscopy. Acad Radiol 2000; 7:971-8. [PMID: 11089700 DOI: 10.1016/s1076-6332(00)80180-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
OBJECTIVES Emotional factors are generally recognized as impacting the care of end-stage heart disease and mortality following cardiac transplants. Equally important, however, are predictors of pretransplant mortality. The current study examined the utility of the Millon Behavioral Health Inventory (MBHI) as a predictor of pre- and posttransplant mortality. METHODS A total of 103 cardiac transplant candidates were assessed with the MBHI as part of a pretransplant evaluation that included baseline demographic variables and cardiac status. Time to transplant and mortality status at 1 and 5 years was also obtained. RESULTS Cluster analysis of MBHI response scores elicited two clusters characterized by high and low distress. Cluster membership predicted survival status at 1-year and 5-year follow-up, with high distress cluster patients having significantly higher mortality in both the total sample and a subgroup of patients who did receive a heart transplant. CONCLUSIONS These results support the value of the MBHI for assessing personality attributes that may dispose toward unfavorable outcome in heart transplant candidates. Further understanding of psychosocial contributions to illness course and outcome may enable more effective selection of treatment interventions with cardiac patients.
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Scintillation proximity assay for E-, P-, and L-selectin utilizing polyacrylamide-based neoglycoconjugates as ligands. Anal Biochem 1998; 258:127-35. [PMID: 9527858 DOI: 10.1006/abio.1998.2576] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, a novel scintillation proximity assay (SPA) that uses radiolabeled soluble neoglycoconjugates as synthetic alternatives to the natural E-, P-, and L-selectin counterligands was developed. The neoglycoconjugates contained sialyl LewisX or sialyl LewisA attached via a three-carbon spacer to a poly[N-(hydroxyethyl)acrylamide] backbone, thus presenting the carbohydrates in a multivalent form. Selectin-ZZ fusion proteins were immobilized on anti-rabbit IgG-coated SPA beads via a rabbit IgG bridge. The neoglycoconjugate ligands bound to all three bead-immobilized selectins, with the highest binding levels apparent with E-selectin. Saturation binding studies with E-selectin revealed a complex interaction indicative of two or more binding affinities. The response to carbohydrate inhibitors was comparable in E-selectin assays that used either the neoglycoconjugates or the tritium-labeled HL60 cells as selectin counterligands. The incorporation of tyrosine sulfate groups into the backbone of the neoglycoconjugate resulted in enhanced binding avidity to both P- and L-selectin, indicating that the sulfate-containing neoglycoconjugates are viable synthetic mimics of the natural P- and L-selectin counterligands. The use of these radiolabeled neoglycoconjugates in conjunction with SPA results in a format ideally suited for the high-throughput screening for selectin antagonists. Furthermore, this approach can potentially be used to measure other low-avidity lectin-carbohydrate interactions.
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Front page splash. Interview by Richard Morris. NURSING TIMES 1997; 93:24-5. [PMID: 9188415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Maximum effect. Nurs Stand 1997; 11:18. [PMID: 9110756 DOI: 10.7748/ns.11.19.18.s32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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The vegetarian opportunity. FOOD MANAGEMENT 1993; 28:40. [PMID: 10128373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Characterisation of chlorogenic acids by simultaneous isomerisation and transesterification with tetramethylammonium hydroxide. Food Chem 1989. [DOI: 10.1016/0308-8146(89)90114-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Neural control of limb coordination. I. Comparison of hatching and walking motor output patterns in normal and deafferented chicks. J Neurosci 1987; 7:2320-30. [PMID: 3612243 PMCID: PMC6568956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Previous work has shown that the neural circuits underlying the leg movements of walking and hatching coexist in post-hatching chicks (Bekoff and Kauer, 1984). In the present study, quantitative analysis of leg EMGs shows that there are some similarities, but also significant differences, in the motor output patterns of walking and hatching. This study examines the effect of removing sensory feedback from the legs on the production of the distinctive leg motor patterns. The temporal characteristics and interlimb coordination of hatching and walking are little affected. However, major changes in intralimb motor output patterns are seen when compared to records from normal chicks. These changes fall into one of 2 categories. Some parameters show similar changes in both behaviors after deafferentation (e.g., increases in flexor burst durations and cycle period). This suggests that certain features of sensory input from the legs normally modulate the hatching and walking pattern-generating circuitry in similar ways. Other parameters show convergence. That is, these aspects of the 2 intralimb motor patterns become more similar to each other after removal of sensory input. This is consistent with the hypothesis that some feature of sensory input from the legs normally modulates one set of multiuse intralimb circuitry to produce different output patterns. In general, the walking pattern becomes more like hatching after deafferentation, rather than the reverse, which suggests that the hatching pattern is a more basic one. The maintenance of some residual differences in intralimb motor patterns after leg deafferentation suggests that other sources of modulation must also be involved, or that there are some additional elements of circuitry that are called into play during the normal production of walking and hatching.
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Social and psychological problems associated with clefts: motivations for cleft palate treatment. Int Dent J 1986; 36:115-9. [PMID: 3464565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Adolescents probably constitute a significant proportion of patient case loads for well-established cleft palate teams. Most teenagers return for periodic recall and continue to do so until they are discharged by the team. The proposition that social and psychological dissatisfactions might coalesce during adolescence and influence young people to stop treatment was examined. The modest drop-out rate argues against this contention. An alternative explanation for the low drop-out rate stresses that these patients are poorly equipped psychologically to deal with their clefts during any period of development. Maladaptation is brought into adolescence, influencing some patients to discontinue team treatment. Since most adolescents remain in treatment, it is suggested they do so because it is in their best interests or because there are no other reasonable alternatives. Adolescents who are knowledgeable about their clefts and the purpose of cleft palate teams may view treatment as a necessary and logical sequence of events designed ultimately to enhance appearance and function. For these adolescents, the goals of treatment are in keeping with existing well differentiated self-concepts and body images. It can be argued that prior good psychological adaptation to having a cleft, provides adolescents with a solid base upon which to cope effectively with the subsequent challenges of adolescence.
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Abstract
Information is presented from a psychometric study using a semantic differential to measure the meaning of concepts related to breast reconstruction. One hundred five women participated. All were experiencing breast reconstruction subsequent to mastectomy. The average woman was married, middle-aged, and had 11/2 years of education beyond high school. Results from the semantic differential demonstrated that the women viewed themselves, their bodies, and their femininity positively. They valued themselves, and their self-concepts were closer in meaning to health than to mastectomy, death, or cancer.
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Group therapy for seriously disturbed boys in residential treatment. CHILD WELFARE 1980; 59:560-565. [PMID: 7428489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A group therapy experiment for boys aged 7 through 11 in a residential setting pointed up some key factors and techniques in this kind of intervention.
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Breast reconstruction following mastectomy: II. Marital characteristics of patients seeking the procedure. Ann Plast Surg 1980; 5:344-6. [PMID: 7458173 DOI: 10.1097/00000637-198011000-00002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Information is presented from a clinical study of 65 women and a psychometric study of 85 women. All had had mastectomies because of breast cancer and were reconstruction patients at Duke Hospital. Women seeking breast reconstruction did not exhibit characterological problems. Relatively few were in psychiatric treatment, and previous research had established the presence of positive rather than negative self-images. The marriages of women seeking this surgical procedure were positively and the women viewed their marriages as a chief source of support. Considerable satisfaction was expressed about husbands being supportive, although husbands were also viewed as poor listeners and, at times, as unable to communicate effectively. Most women were satisfied with various aspects of their sexual lives. A small percentage of the women reported problematic marriages. Various factors, related to the presence of conflict in the marriage and the ability of the husband to understand his wife, may account for the distress evidenced in these marriages. Such factors, of course, are present in any problematic marriage; it remains to be demonstrated whether these problems were caused or exacerbated by the woman's mastectomy and decision to seek breast reconstruction.
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Breast reconstruction following mastectomy: I. Social characteristics of patients seeking the procedure. Ann Plast Surg 1980; 5:341-3. [PMID: 7458172 DOI: 10.1097/00000637-198011000-00001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Information is presented from a clinical study of 65 women and a psychometric study of 85 women having breast reconstruction following mastectomy for breast cancer. The average woman was in her midforties. Less than a third of the women described themselves as fulltime housewives; most were employed outside the home. Almost all had completed high school and most had received additional education. Most of the women were married when they sought breast reconstruction. The time at which women had had their mastectomies was related to their source of information about breast reconstruction. When more than five years had elapsed between mastectomy and reconstruction, a woman most often had obtained her information from the media. Women with more recent mastectomies, though utilizing the media, obtained their information more frequently from medical sources.
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Self-concepts before and after survival training. THE BRITISH JOURNAL OF SOCIAL AND CLINICAL PSYCHOLOGY 1967; 6:241-8. [PMID: 6080233 DOI: 10.1111/j.2044-8260.1967.tb00526.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Bernard Johnson Memorial. West J Med 1960. [DOI: 10.1136/bmj.1.5176.883-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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