50 results on '"Hutchinson, DJ"'
Search Results
2. Residents’ perceptions of sustainable drainage systems as highly functional blue green infrastructure
- Author
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Williams, JB, Jose, R, Moobela, C, Hutchinson, DJ, Wise, R, Gaterell, M, Williams, JB, Jose, R, Moobela, C, Hutchinson, DJ, Wise, R, and Gaterell, M
- Abstract
© 2019 The Authors Blue-green infrastructure for storm water management in the UK is considered to be part of Sustainable Drainage Systems (SuDS). Design guidance recommends that source control and treatment trains are embedded within developments. This means that residents live next to SuDS performing functions such as infiltration, conveyance and storage. In addition to hydraulic attenuation, SuDS can provide benefits such as water quality improvement, wildlife habitat and amenity. However, economic pressure to maximise development opportunity means that designs do not always maximise these benefits. Therefore, residents’ perceptions of the benefits and problems of living with SuDS are important as these may affect residential property values and willingness to pay management fees, which could justify high quality designs that deliver multiple benefits. This study aimed to investigate these issues through a survey of residents living with SuDS across six housing developments in England, 406/2916 responses were collected. The developments had good quality SuDS, with an established residential population and active housing market. The residents had varied levels of awareness of the presence and function of SuDS. Generally, residents liked the wildlife and green space but this was tempered with concerns over pests (rats and mosquitoes) and litter. Maintenance of SuDS was also an issue and at three sites residents were charged management fees which were not well understood and caused concern. The majority of residents were unwilling to contribute more to maintenance. Most residents and local estate agents did not perceive that SuDS increased property values. Raising awareness of the benefits of SuDS may lead to greater acceptance by residents and encourage developers to include them in developments, which could contribute to overcoming one of the barriers to wider implementation.
- Published
- 2019
3. Slow rock-slope deformation
- Author
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Clague, JJ, Stead, D, Roberts, N, Korup, O., Hovius, N, Meunier, P, Waythomas, CF, Davies, T, McSaveney, M, Hermanns, RL, Longva, O, Jakob, M, Holm, K, Torrance, JK, Piper, DJW, Mosher, DC, Campbell, DC, Bornhold, BD, Thomson, RE, Huggel, C, Khabarov, N, Obersteiner, M, Fell, R, Stapledon, D, MacGregor, P, Coggan, J, Petley, D, Griffiths, JS, Whitworth, M, McDougall, S, McKinnon, M, Hungr, O, Jibson, RW, Agliardi, F, Crosta, GB, Frattini, P, Eberhardt, E, Picarelli, L, Leroueil, S, Olivares, L, Pagano, L, Tommasi, P, Urciuoli, G, Bromhead, EN, Hosseyni, S, Torii, N, Jaboyedoff, M, Derron, MH, Jakubowski, J, Oppikofer, T, Pedrazzini, A, Loew, S, Gischig, V, Willenberg, H, Alpiger, A, Moore, JR, Froese, CR, Charrière, M, Humair, F, Blikra, LH, Bianchi Fasani,G, Esposito, C, Lenti, L, Martino, S, Pecci, M, Scarascia Mugnozza, G, Kalenchuk, KS, Hutchinson, DJ, Diederichs, M, Moore, D, Ghirotti, M, Hencher, SR, Malone, AW, Chigira, M, Wang, G, Wu, X, Bulmer, MHK, Crosta, G, AGLIARDI, FEDERICO, CROSTA, GIOVANNI, FRATTINI, PAOLO, Clague, JJ, Stead, D, Roberts, N, Korup, O., Hovius, N, Meunier, P, Waythomas, CF, Davies, T, McSaveney, M, Hermanns, RL, Longva, O, Jakob, M, Holm, K, Torrance, JK, Piper, DJW, Mosher, DC, Campbell, DC, Bornhold, BD, Thomson, RE, Huggel, C, Khabarov, N, Obersteiner, M, Fell, R, Stapledon, D, MacGregor, P, Coggan, J, Petley, D, Griffiths, JS, Whitworth, M, McDougall, S, McKinnon, M, Hungr, O, Jibson, RW, Agliardi, F, Crosta, GB, Frattini, P, Eberhardt, E, Picarelli, L, Leroueil, S, Olivares, L, Pagano, L, Tommasi, P, Urciuoli, G, Bromhead, EN, Hosseyni, S, Torii, N, Jaboyedoff, M, Derron, MH, Jakubowski, J, Oppikofer, T, Pedrazzini, A, Loew, S, Gischig, V, Willenberg, H, Alpiger, A, Moore, JR, Froese, CR, Charrière, M, Humair, F, Blikra, LH, Bianchi Fasani,G, Esposito, C, Lenti, L, Martino, S, Pecci, M, Scarascia Mugnozza, G, Kalenchuk, KS, Hutchinson, DJ, Diederichs, M, Moore, D, Ghirotti, M, Hencher, SR, Malone, AW, Chigira, M, Wang, G, Wu, X, Bulmer, MHK, Crosta, G, AGLIARDI, FEDERICO, CROSTA, GIOVANNI, and FRATTINI, PAOLO
- Abstract
Giant, deep-seated gravitational slope deformations (DSGSD) affecting entire high-relief valley walls are common in alpine areas, and influence the evolution of mountain landscapes and the related hazards. In the last few years, new characterisation approaches and emerging technology shed new light on the occurrence, distribution, activity, and mechanisms of these spectacular slope failures. This chapter is aimed at providing an overview of alpine DSGSD, as well as a discussion of outstanding issues and future research needs. We review the definition of DSGSD and its typical features, field evidence, settings, and mechanisms. We discuss the distribution and controls on DSGSD occurrence based on the analysis of the first-ever orogen-scale inventory of these phenomena, including over 900 individual phenomena in the European Alps. We demonstrate that DSGSDs are widespread in active orogenic settings and chiefly occur in formerly glaciated areas under significant structural controls, and show that alpine DSGSDs are often active phenomena with a engineering significance. We use the emblematic case study of the Cima di Mandriole sackung to illustrate the complex relations among rock structure, the morpho-climatic evolution of Alpine valleys, and man-made structures, and point out future research needs.
- Published
- 2012
4. Rockfall characterization and modeling
- Author
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Clague, JJ, Stead, D, Roberts, N, Korup, O., Hovius, N, Meunier, P, Waythomas, CF, Davies, T, McSaveney, M, Hermanns, RL, Longva, O, Jakob, M, Holm, K, Torrance, JK, Piper, DJW, Mosher, DC, Campbell, DC, Bornhold, BD, Thomson, RE, Huggel, C, Khabarov, N, Obersteiner, M, Fell, R, Stapledon, D, MacGregor, P, Coggan, J, Petley, D, Griffiths, JS, Whitworth, M, McDougall, S, McKinnon, M, Hungr, O, Jibson, RW, Agliardi, F, Crosta, GB, Frattini, P, Eberhardt, E, Picarelli, L, Leroueil, S, Olivares, L, Pagano, L, Tommasi, P, Urciuoli, G, Bromhead, EN, Hosseyni, S, Torii, N, Jaboyedoff, M, Derron, MH, Jakubowski, J, Oppikofer, T, Pedrazzini, A, Loew, S, Gischig, V, Willenberg, H, Alpiger, A, Moore, JR, Froese, CR, Charrière, M, Humair, F, Blikra, LH, Bianchi Fasani,G, Esposito, C, Lenti, L, Martino, S, Pecci, M, Scarascia Mugnozza, G, Kalenchuk, KS, Hutchinson, DJ, Diederichs, M, Moore, D, Ghirotti, M, Hencher, SR, Malone, AW, Chigira, M, Wang, G, Wu, X, Bulmer, MHK, Crosta, G, FRATTINI, PAOLO, CROSTA, GIOVANNI, AGLIARDI, FEDERICO, Clague, JJ, Stead, D, Roberts, N, Korup, O., Hovius, N, Meunier, P, Waythomas, CF, Davies, T, McSaveney, M, Hermanns, RL, Longva, O, Jakob, M, Holm, K, Torrance, JK, Piper, DJW, Mosher, DC, Campbell, DC, Bornhold, BD, Thomson, RE, Huggel, C, Khabarov, N, Obersteiner, M, Fell, R, Stapledon, D, MacGregor, P, Coggan, J, Petley, D, Griffiths, JS, Whitworth, M, McDougall, S, McKinnon, M, Hungr, O, Jibson, RW, Agliardi, F, Crosta, GB, Frattini, P, Eberhardt, E, Picarelli, L, Leroueil, S, Olivares, L, Pagano, L, Tommasi, P, Urciuoli, G, Bromhead, EN, Hosseyni, S, Torii, N, Jaboyedoff, M, Derron, MH, Jakubowski, J, Oppikofer, T, Pedrazzini, A, Loew, S, Gischig, V, Willenberg, H, Alpiger, A, Moore, JR, Froese, CR, Charrière, M, Humair, F, Blikra, LH, Bianchi Fasani,G, Esposito, C, Lenti, L, Martino, S, Pecci, M, Scarascia Mugnozza, G, Kalenchuk, KS, Hutchinson, DJ, Diederichs, M, Moore, D, Ghirotti, M, Hencher, SR, Malone, AW, Chigira, M, Wang, G, Wu, X, Bulmer, MHK, Crosta, G, FRATTINI, PAOLO, CROSTA, GIOVANNI, and AGLIARDI, FEDERICO
- Abstract
Rockfalls pose a significant threat to life and property, although significant advances in rockfall protection have been made in the past decade. Determining rockfall processes and related hazard, however, remains a difficult task, because of the complexity and intrinsic stochastic nature of the physics involved. Appropriate application of rockfall modelling tools requires a thorough understanding of their logic, assumptions, advantages, and limitations, as well as careful assessment of rockfall sources, block and slope characteristics, and model calibration data. This chapter provides a discussion of major issues in rockfall definition, characterisation, and modelling, with special emphasis on rockfall runout. Our discussion is supported by modelling examples carried out using the 3D simulator Hy-STONE. Different modelling approaches are critically evaluated, including the empirical shadow angle method, and 2D and 3D mathematical models. Application of the shadow angle concept requires the user to be aware of several issues related to definition of the shadow angle and the effects of morphological constraints. Most limitations of empirical approaches can be overcome with mathematical models that account for slope morphology and roughness, energy dissipation at impact or by rolling, and the effects of vegetation, block fragmentation, and block-structure interaction. We discuss different modelling approaches and calibration problems and the important dependency of model parameters and results on correct characterisation of topography.
- Published
- 2012
5. Stability of extemporaneously prepared rufinamide oral suspensions.
- Author
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Hutchinson DJ, Liou Y, Best R, and Zhao F
- Published
- 2010
- Full Text
- View/download PDF
6. Rockfall characterization and modeling
- Author
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Paolo Frattini, Giovanni B. Crosta, Federico Agliardi, Clague, JJ, Stead, D, Roberts, N, Korup, O., Hovius, N, Meunier, P, Waythomas, CF, Davies, T, McSaveney, M, Hermanns, RL, Longva, O, Jakob, M, Holm, K, Torrance, JK, Piper, DJW, Mosher, DC, Campbell, DC, Bornhold, BD, Thomson, RE, Huggel, C, Khabarov, N, Obersteiner, M, Fell, R, Stapledon, D, MacGregor, P, Coggan, J, Petley, D, Griffiths, JS, Whitworth, M, McDougall, S, McKinnon, M, Hungr, O, Jibson, RW, Agliardi, F, Crosta, GB, Frattini, P, Eberhardt, E, Picarelli, L, Leroueil, S, Olivares, L, Pagano, L, Tommasi, P, Urciuoli, G, Bromhead, EN, Hosseyni, S, Torii, N, Jaboyedoff, M, Derron, MH, Jakubowski, J, Oppikofer, T, Pedrazzini, A, Loew, S, Gischig, V, Willenberg, H, Alpiger, A, Moore, JR, Froese, CR, Charrière, M, Humair, F, Blikra, LH, Bianchi Fasani,G, Esposito, C, Lenti, L, Martino, S, Pecci, M, Scarascia Mugnozza, G, Kalenchuk, KS, Hutchinson, DJ, Diederichs, M, Moore, D, Ghirotti, M, Hencher, SR, Malone, AW, Chigira, M, Wang, G, Wu, X, Bulmer, MHK, and Crosta, G
- Subjects
geography ,Rockfall ,geography.geographical_feature_category ,Geotechnical engineering ,rockfall, modeling, 3D, hazard, impact, fragmentation, energy line ,Geology ,GEO/05 - GEOLOGIA APPLICATA - Abstract
Rockfalls pose a significant threat to life and property, although significant advances in rockfall protection have been made in the past decade. Determining rockfall processes and related hazard, however, remains a difficult task, because of the complexity and intrinsic stochastic nature of the physics involved. Appropriate application of rockfall modelling tools requires a thorough understanding of their logic, assumptions, advantages, and limitations, as well as careful assessment of rockfall sources, block and slope characteristics, and model calibration data. This chapter provides a discussion of major issues in rockfall definition, characterisation, and modelling, with special emphasis on rockfall runout. Our discussion is supported by modelling examples carried out using the 3D simulator Hy-STONE. Different modelling approaches are critically evaluated, including the empirical shadow angle method, and 2D and 3D mathematical models. Application of the shadow angle concept requires the user to be aware of several issues related to definition of the shadow angle and the effects of morphological constraints. Most limitations of empirical approaches can be overcome with mathematical models that account for slope morphology and roughness, energy dissipation at impact or by rolling, and the effects of vegetation, block fragmentation, and block-structure interaction. We discuss different modelling approaches and calibration problems and the important dependency of model parameters and results on correct characterisation of topography.
- Published
- 2012
7. Slow rock-slope deformation
- Author
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Giovanni B. Crosta, Federico Agliardi, Paolo Frattini, Clague, JJ, Stead, D, Roberts, N, Korup, O., Hovius, N, Meunier, P, Waythomas, CF, Davies, T, McSaveney, M, Hermanns, RL, Longva, O, Jakob, M, Holm, K, Torrance, JK, Piper, DJW, Mosher, DC, Campbell, DC, Bornhold, BD, Thomson, RE, Huggel, C, Khabarov, N, Obersteiner, M, Fell, R, Stapledon, D, MacGregor, P, Coggan, J, Petley, D, Griffiths, JS, Whitworth, M, McDougall, S, McKinnon, M, Hungr, O, Jibson, RW, Agliardi, F, Crosta, GB, Frattini, P, Eberhardt, E, Picarelli, L, Leroueil, S, Olivares, L, Pagano, L, Tommasi, P, Urciuoli, G, Bromhead, EN, Hosseyni, S, Torii, N, Jaboyedoff, M, Derron, MH, Jakubowski, J, Oppikofer, T, Pedrazzini, A, Loew, S, Gischig, V, Willenberg, H, Alpiger, A, Moore, JR, Froese, CR, Charrière, M, Humair, F, Blikra, LH, Bianchi Fasani,G, Esposito, C, Lenti, L, Martino, S, Pecci, M, Scarascia Mugnozza, G, Kalenchuk, KS, Hutchinson, DJ, Diederichs, M, Moore, D, Ghirotti, M, Hencher, SR, Malone, AW, Chigira, M, Wang, G, Wu, X, Bulmer, MHK, and Crosta, G
- Subjects
geography ,geography.geographical_feature_category ,Landslide classification ,deep seated slope deformation, landslide, inventory, modeling, slope-struvture interation ,Rockslide ,Deformation (meteorology) ,GEO/05 - GEOLOGIA APPLICATA ,Slump ,Rockfall ,Creep ,Interferometric synthetic aperture radar ,Geotechnical engineering ,Shear strength (discontinuity) ,Geomorphology ,Geology - Abstract
Giant, deep-seated gravitational slope deformations (DSGSD) affecting entire high-relief valley walls are common in alpine areas, and influence the evolution of mountain landscapes and the related hazards. In the last few years, new characterisation approaches and emerging technology shed new light on the occurrence, distribution, activity, and mechanisms of these spectacular slope failures. This chapter is aimed at providing an overview of alpine DSGSD, as well as a discussion of outstanding issues and future research needs. We review the definition of DSGSD and its typical features, field evidence, settings, and mechanisms. We discuss the distribution and controls on DSGSD occurrence based on the analysis of the first-ever orogen-scale inventory of these phenomena, including over 900 individual phenomena in the European Alps. We demonstrate that DSGSDs are widespread in active orogenic settings and chiefly occur in formerly glaciated areas under significant structural controls, and show that alpine DSGSDs are often active phenomena with a engineering significance. We use the emblematic case study of the Cima di Mandriole sackung to illustrate the complex relations among rock structure, the morpho-climatic evolution of Alpine valleys, and man-made structures, and point out future research needs.
- Published
- 2012
8. Synthesis, evaluation and modification of heterofunctional polyester dendrimers with internally queued bromide groups.
- Author
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Singh A, Hutchinson DJ, Montañez MI, Sanz Del Olmo N, and Malkoch M
- Abstract
Heterofunctional polyester dendrimers up to the third generation, containing 21 internally queued bromine atoms, have been successfully synthesized for the first time using a divergent growth approach. Direct azidation reactions enabled the conversion of the bromide groups to clickable azide pendant functionalities. Therapeutic and chemical moeities could then be coupled to the internal azide or bromide functionalities and external hydroxyl groups of the heterofunctional dendrimers through CuAAC, thiol-bromo click and esterification reactions, expanding their potential for biomedical applications.
- Published
- 2024
- Full Text
- View/download PDF
9. Photo-Clickable Triazine-Trione Thermosets as Promising 3D Scaffolds for Tissue Engineering Applications.
- Author
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Johansen Å, Lin J, Yamada S, Mohamed-Ahmed S, Yassin MA, Gjerde C, Hutchinson DJ, Mustafa K, and Malkoch M
- Subjects
- Animals, Cell Proliferation drug effects, Printing, Three-Dimensional, Biocompatible Materials chemistry, Biocompatible Materials pharmacology, Click Chemistry methods, Tissue Engineering methods, Tissue Scaffolds chemistry, Triazines chemistry, Triazines pharmacology, Mesenchymal Stem Cells cytology
- Abstract
There is an overwhelming demand for new scaffolding materials for tissue engineering (TE) purposes. Polymeric scaffolds have been explored as TE materials; however, their high glass transition state (T
g ) limits their applicability. In this study, a novel materials platform for fabricating TE scaffolds is proposed based on solvent-free two-component heterocyclic triazine-trione (TATO) formulations, which cure at room temperature via thiol-ene/yne photochemistry. Three ester-containing thermosets, TATO-1, TATO-2, and TATO-3, are used for the fabrication of TE scaffolds including rigid discs, elastic films, microporous sponges, and 3D printed objects. After 14 days' incubation the materials covered a wide range of properties, from the soft TATO-2 having a compression modulus of 19.3 MPa and a Tg of 30.4 °C to the hard TATO-3 having a compression modulus of 411 MPa and a Tg of 62.5 °C. All materials exhibit micro- and nano-surface morphologies suited for bone tissue engineering, and in vitro studies found them all to be cytocompatible, supporting fast cell proliferation while minimizing cell apoptosis and necrosis. Moreover, bone marrow-derived mesenchymal stem cells on the surface of the materials are successfully differentiated into osteoblasts, adipocytes, and neuronal cells, underlining the broad potential for the biofabrication of TATO materials for TE clinical applications., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)- Published
- 2024
- Full Text
- View/download PDF
10. Determination of the internal loads experienced by proximal phalanx fracture fixations during rehabilitation exercises.
- Author
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Schwarzenberg P, Colding-Rasmussen T, Hutchinson DJ, San Jacinto Garcia J, Granskog V, Mørk Petersen M, Pastor T, Weis T, Malkoch M, Nai En Tierp-Wong C, and Varga P
- Abstract
Phalangeal fractures are common, particularly in younger patients, leading to a large economic burden due to higher incident rates among patients of working age. In traumatic cases where the fracture may be unstable, plate fixation has grown in popularity due to its greater construct rigidity. However, these metal plates have increased reoperation rates due to inflammation of the surrounding soft tissue. To overcome these challenges, a novel osteosynthesis platform, AdhFix, has been developed. This method uses a light-curable polymer that can be shaped in situ around traditional metal screws to create a plate-like structure that has been shown to not induce soft tissue adhesions. However, to effectively evaluate any novel osteosynthesis device, the biomechanical environment must first be understood. In this study, the internal loads in a phalangeal plate osteosynthesis were measured under simulated rehabilitation exercises. In a human hand cadaver study, a plastic plate with known biomechanical properties was used to fix a 3 mm osteotomy and each finger was fully flexed to mimic traditional rehabilitation exercises. The displacements of the bone fragments were tracked with a stereographic camera system and coupled with specimen specific finite element (FE) models to calculate the internal loads in the osteosynthesis. Following this, AdhFix patches were created and monotonically tested under similar conditions to determine survival of the novel technique. The internal bending moment in the osteosynthesis was 6.78 ± 1.62 Nmm and none of the AdhFix patches failed under the monotonic rehabilitation exercises. This study demonstrates a method to calculate the internal loads on an osteosynthesis device during non-load bearing exercises and that the novel AdhFix solution did not fail under traditional rehabilitation protocols in this controlled setting. Further studies are required prior to clinical application., Competing Interests: MM and VG are involved in Biomedical Bonding AB, which aims to aid patients with adhesive fixators as an alternative to current commercial metal implants. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Schwarzenberg, Colding-Rasmussen, Hutchinson, San Jacinto Garcia, Granskog, Mørk Petersen, Pastor, Weis, Malkoch, Nai En Tierp-Wong and Varga.)
- Published
- 2024
- Full Text
- View/download PDF
11. Enhanced Degradability of Thiol-Ene Composites through the Inclusion of Isosorbide-Based Polycarbonates.
- Author
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San Jacinto Garcia J, Sanz Del Olmo N, Hutchinson DJ, and Malkoch M
- Subjects
- Sulfhydryl Compounds chemistry, Humans, Materials Testing, Biocompatible Materials chemistry, Biocompatible Materials chemical synthesis, Isosorbide chemistry, Polyesters chemistry
- Abstract
Open reduction internal fixation metal plates and screws remain the established standard-of-care for complex fracture fixation. They, however, have drawbacks such as limited customization, soft-tissue adhesions, and a lack of degradation. Bone cements and composites are being developed as alternative fixation techniques in order to overcome these issues. One such composite is a strong, stiff, and shapeable hydroxyapatite-containing material consisting of 1,3,5-triazine-2,4,6-trione (TATO) monomers, which cures through high energy visible light-induced thiol-ene coupling (TEC) chemistry. Previous human cadaver and in vivo studies have shown that patches of this composite provide sufficient fixation for healing bone fractures; however, the composite lacks degradability. To promote degradation through hydrolysis, new allyl-functionalized isosorbide-based polycarbonates have been added into the composite formulation, and their impact has been evaluated. Three polycarbonates with allyl functionalities, located at the termini (aPC1 and aPC2) or in the backbone (aPC3), were synthesized. Composites containing 1, 3, and 5 wt % of aPCs 1-3 were formulated and evaluated with regard to mechanical properties, water absorption, hydrolytic degradation, and cytotoxicity. Allyl-functionalized polycaprolactone (aPCL) was synthesized and used as a comparison. When integrated into the composite, aPC3 significantly impacted the material's properties, with the 5 wt % aPC3 formulation showing a significant increase in degradation of 469%, relative to the formulation not containing any aPCs after 8 weeks' immersion in PBS, along with a modest decrease in modulus of 28% to 4.01 (0.3) GPa. Osteosyntheses combining the aPC3 3 and 5 wt % formulations with screws on synthetic bones with ostectomies matched or outperformed the ones made with the previously studied neat composite with regard to bending stiffness and strength in four-point monotonic bending before and after immersion in PBS. The favorable mechanical properties, increased degradation, and nontoxic characteristics of the materials present aPC3 as a promising additive for the TATO composite formulations. This combination resulted in stiff composites with long-term degradation that are suitable for bone fracture repair.
- Published
- 2024
- Full Text
- View/download PDF
12. Previously hidden landslide processes revealed using distributed acoustic sensing with nanostrain-rate sensitivity.
- Author
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Ouellet SM, Dettmer J, Lato MJ, Cole S, Hutchinson DJ, Karrenbach M, Dashwood B, Chambers JE, and Crickmore R
- Abstract
Landslides sometimes creep for decades before undergoing runaway acceleration and catastrophic failure. Observing and monitoring the evolution of strain in time and space is crucial to understand landslide processes, including the transition from slow to fast movement. However, the limited spatial or temporal resolution of existing landslide monitoring instrumentation limits the study of these processes. We employ distributed acoustic sensing strain data below 1 Hertz frequency during a three-day rainfall at the Hollin Hill landslide and quantify strain-rate changes at meter and sub-minute scales. We observe near-surface strain onset at the head scarp, strain acceleration at a developing rupture zone, retrogression towards the scarp, and flow-lobe activity. These processes with displacements of less than 0.5 mm are undetected using other methods. However, the millimeter processes over three days agree with previously observed seasonal landslide patterns. Here, we show landslide processes occurring with nanostrain-rate sensitivity at spatiotemporal resolution previously not possible., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
13. Antibacterial Hydrogel Adhesives Based on Bifunctional Telechelic Dendritic-Linear-Dendritic Block Copolymers.
- Author
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Sanz Del Olmo N, Molina N, Fan Y, Namata F, Hutchinson DJ, and Malkoch M
- Subjects
- Dendrimers chemistry, Dendrimers pharmacology, Microbial Sensitivity Tests, Adhesives chemistry, Adhesives pharmacology, Polyethylene Glycols chemistry, Polyethylene Glycols pharmacology, Polymers chemistry, Polymers pharmacology, Humans, Molecular Structure, Click Chemistry, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents chemical synthesis, Hydrogels chemistry, Hydrogels pharmacology, Hydrogels chemical synthesis
- Abstract
Antibiotic-resistant pathogens have been declared by the WHO as one of the major public health threats facing humanity. For that reason, there is an urgent need for materials with inherent antibacterial activity able to replace the use of antibiotics, and in this context, hydrogels have emerged as a promising strategy. Herein, we introduce the next generation of cationic hydrogels with antibacterial activity and high versatility that can be cured on demand in less than 20 s using thiol-ene click chemistry (TEC) in aqueous conditions. The approach capitalizes on a two-component system: (i) telechelic polyester-based dendritic-linear-dendritic (DLDs) block copolymers of different generations heterofunctionalized with allyl and ammonium groups, as well as (ii) polyethylene glycol (PEG) cross-linkers functionalized with thiol groups. These hydrogels resulted in highly tunable materials where the antibacterial performance can be adjusted by modifying the cross-linking density. Off-stoichiometric hydrogels showed narrow antibacterial activity directed toward Gram-negative bacteria. The presence of pending allyls opens up many possibilities for functionalization with biologically interesting molecules. As a proof-of-concept, hydrophilic cysteamine hydrochloride as well as N-hexyl-4-mercaptobutanamide, as an example of a thiol with a hydrophobic alkyl chain, generated three-component networks. In the case of cysteamine derivatives, a broader antibacterial activity was noted than the two-component networks, inhibiting the growth of Gram-positive bacteria. Additionally, these systems presented high versatility, with storage modulus values ranging from 270 to 7024 Pa and different stability profiles ranging from 1 to 56 days in swelling experiments. Good biocompatibility toward skin cells as well as strong adhesion to multiple surfaces place these hydrogels as interesting alternatives to conventional antibiotics.
- Published
- 2024
- Full Text
- View/download PDF
14. Effect of Dexmedetomidine on Incidence of Hypertension Following Repair of Coarctation of the Aorta.
- Author
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Abarintos HML, Kapuscinski CA, Wheaton T, Stauber SD, Swartz MF, Grossman M, Masri S, and Hutchinson DJ
- Abstract
Objective: Recent literature suggests a potential role for dexmedetomidine in reducing the incidence and severity of hypertension following repair of coarctation of the aorta (CoA). The primary aim of this study was to assess the association between dexmedetomidine use and the incidence of hypertension following repair of CoA in pediatric patients., Methods: This was a single-center, retrospective cohort study in patients younger than 19 years who underwent surgical repair of CoA between January 1, 2016, and September 30, 2021. Patients were divided into 2 groups: dexmedetomidine initiation within the first 3 hours after surgery or no dexmedetomidine. The primary outcome was incidence of hypertension within the first 4 to 24 hours after repair. Secondary outcomes included the incidence of hypotension and bradycardia., Results: A total of 80 patients were included, 25 (31.25%) received dexmedetomidine. Median age at the time of procedure was 26 days (IQR, 13-241) in the dexmedetomidine group and 14 days (IQR, 8-53) in the no dexmedetomidine group (p = 0.014). The primary outcome of hypertension was met in 7 patients (28%) in the dexmedetomidine group and 12 patients (21.8%) in the no dexmedetomidine group, p = 0.547. The only variable found to be associated with the incidence of hypertension was age greater than 30 days at the time of procedure. More patients who received dexmedetomidine experienced bradycardia. There was no difference in the incidence of hypotension., Conclusions: There was no association between the use of dexmedetomidine and the incidence of -hypertension following repair of CoA in pediatric patients., Competing Interests: Disclosure. The authors declare no conflicts or financial interest in any product or service mentioned in the manuscript, including grants, equipment, medications, employment, gifts, and honoraria. The authors had full access to all the data and take responsibility for the integrity and the accuracy of the data analysis., (Copyright. Pediatric Pharmacy Association. All rights reserved. For permissions, email: membership@pediatricpharmacy.org.)
- Published
- 2024
- Full Text
- View/download PDF
15. Adjunctive fixation of the humeral epicondyle in a lateral condylar fracture model: Ex vivo comparison of pins and plates with a novel composite (AdhFix).
- Author
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Quinn RJ, Höglund OV, Hutchinson DJ, Opande L, Lim E, Birgersson U, Granskog V, and Malkoch M
- Subjects
- Humans, Animals, Dogs, Fracture Fixation, Internal veterinary, Fracture Fixation, Internal methods, Biomechanical Phenomena, Bone Nails veterinary, Bone Plates veterinary, Humerus surgery, Cadaver, Humeral Fractures surgery, Humeral Fractures veterinary, Dog Diseases
- Abstract
Objective: To compare the biomechanical properties of using a novel composite construct (AdhFix) to an interfragmentary Kirschner wire or a reconstruction plate as adjunctive epicondylar stabilization in simulated lateral unicondylar humeral fractures., Study Design: Cadaveric biomechanical assessment., Sample Population: Paired humeri harvested from skeletally mature dogs (14-41 kg), nine cadavers per group., Methods: Simulated lateral unicondylar humeral fractures were stabilized with a transcondylar 4.5 mm cortical screw placed in lag fashion. Adjunct fixations consisting of a novel composite incorporating 2.7 mm cortical screws on one side, and either a 2.7 mm reconstruction plate or a 1.6 mm Kirschner wire on the contralateral side, were tested within paired humeri. Repaired humeri were axially loaded to failure and construct stiffness, yield load, and ultimate load were obtained from the load-deformation curves., Results: In pairwise comparison, yield load was significantly higher for AdhFix group compared to the pin group, p = .016. No statistical significance was seen in the comparison between AdhFix group and the plate group, p = .25., Conclusion: Adhfix was mechanically superior to K-wires, and comparable to plate fixation, for adjunctive fixation in a lateral humeral condylar model. Our results support further investigation of the novel composite for adjunct fracture fixation in lateral humeral condylar fractures., Clinical Significance: The novel composite tested may be a viable alternative for adjunct fixation of humeral condylar fractures, a technique that circumvents plate contouring., (© 2023 The Authors. Veterinary Surgery published by Wiley Periodicals LLC on behalf of American College of Veterinary Surgeons.)
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- 2024
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16. Current Practices and Safety of Medication Use During Pediatric Rapid Sequence Intubation.
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Bisesi SA, Stauber SD, Hutchinson DJ, and Acquisto NM
- Abstract
Objectives: This study aimed to characterize medication-related practices during and immediately -following rapid sequence intubation (RSI) in pediatric care units across the United States and to evaluate adverse drug events., Methods: This was a multicenter, observational study of medication practices surrounding intubation in pediatric and neonatal intensive care unit (NICU) and emergency department patients across the United States., Results: A total of 172 patients from 13 geographically diverse institutions were included. Overall, 24%, 69%, and 50% received preinduction, induction, and neuromuscular blockade, respectively. Induction and neuromuscular blocking agent (NMBA) use was low in NICU patients (52% and 23%, respectively), whereas nearly all patients intubated outside of the NICU received both (98% and 95%, respectively). NICU patients who received RSI medications were older and weighed more. Despite infrequent use of atropine (21%), only 3 patients developed bradycardia after RSI. Of the 119 patients who received an induction agent, fentanyl (67%) and midazolam (34%) were administered most frequently. Hypotension and hypertension occurred in 23% and 24% of patients, respectively, but were not associated with a single induction agent. Etomidate use was low and not associated with development of adrenal insufficiency. Rocuronium was the most used NMBA (78%). Succinylcholine use was low (11%) and administered despite hyperkalemia in 2 patients. Postintubation sedation and analgesia were not used or inadequate based on timing of initiation in many patients who received a non-depolarizing NMBA., Conclusions: Medication practices surrounding pediatric RSI vary across the United States and may be influenced by patient location, age, and weight., (Copyright. Pediatric Pharmacy Association. All rights reserved. For permissions, email: membership@pediatricpharmacy.org.)
- Published
- 2024
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17. Impact of Polyester Dendrimers as Branched Multifunctional Cross-Linking Additives in Triazine-Trione-Based Composites Developed via High-Energy Visible Light Thiol-ene Chemistry.
- Author
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Lin J, Sanz Del Olmo N, San Jacinto Garcia J, Namata F, Hutchinson DJ, and Malkoch M
- Abstract
Hydroxyapatite (HA) infused triazine-trione (TATO) composites have emerged as an injectable platform for customizable bone fixators due to their fast and benign curing via high-energy visible light-induced thiol-ene chemistry (HEV-TEC), promising mechanical performance, and preclinical outcomes. These composites can overcome many of the existing limitations accompanying metal implants such as poor patient customizability, soft tissue adhesions, and stress shielding. Taking into account that the promising benchmarked TATO composite (BC) is based on stable sulfur-carbon bonds, we herein investigate the impact of introducing polyester dendritic cross-linkers based on bis-MPA as chemically integrated branched additives that display labile esters in a branched configuration. The inclusion of dendrimers, G1 and G3, in concentrations of 1, 3, and 5 wt % in the composite formulations were found to (i) decrease the processing viscosity of the composite formulations, reaching Newtonic and nonshear thinning behavior at 37 °C and (ii) impact the size distribution of bubble cavities in the composite cross sections. The lowest collected T
g for the dendrimer-containing composites was noted to be 73.2 °C, a temperature well above physiological temperature. Additionally, all composites displayed flexural modulus above 6 GPa and flexural strength of ca. 50 MPa under dry conditions. The composites comprising 5 wt % of G1 and G3 dendrimers, with ester bond densities of 0.208 and 0.297 mmol/g, respectively, reached a mass loss up to 0.27% in phosphate buffered saline at 37 °C, which is within the range of established polycaprolactone (PCL). Combined with the nontoxic properties extracted from the cell viability study, polyester dendrimers were determined as promising additives which compatibilized well with the TATO formulation and cross-linked efficiently resulting in strong composites suited for bone fracture fixations., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)- Published
- 2023
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18. Biomechanical Variability and Usability of a Novel Customizable Fracture Fixation Technique.
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Colding-Rasmussen T, Schwarzenberg P, Horstmann PF, Ottesen CBS, Garcia JSJ, Hutchinson DJ, Malkoch M, Petersen MM, Varga P, and Tierp-Wong CNE
- Abstract
A novel in situ customizable osteosynthesis technique, Bonevolent™ AdhFix, demonstrates promising biomechanical properties under the expertise of a single trained operator. This study assesses inter- and intra-surgeon biomechanical variability and usability of the AdhFix osteosynthesis platform. Six surgeons conducted ten osteosyntheses on a synthetic bone fracture model after reviewing an instruction manual and completing one supervised osteosynthesis. Samples underwent 4-point bending tests at a quasi-static loading rate, and the maximum bending moment (BM), bending stiffness (BS), and AdhFix cross-sectional area (CSA: mm²) were evaluated. All constructs exhibited a consistent appearance and were suitable for biomechanical testing. The mean BM was 2.64 ± 0.57 Nm, and the mean BS was 4.35 ± 0.44 Nm/mm. Statistically significant differences were observed among the six surgeons in BM ( p < 0.001) and BS ( p = 0.004). Throughout ten trials, only one surgeon demonstrated a significant improvement in BM ( p < 0.025), and another showed a significant improvement in BS ( p < 0.01). A larger CSA corresponded to a statistically significantly higher value for BM ( p < 0.001) but not for BS ( p = 0.594). In conclusion, this study found consistent biomechanical stability both across and within the surgeons included, suggesting that the AdhFix osteosynthesis platform can be learned and applied with minimal training and, therefore, might be a clinically viable fracture fixation technique. The variability in BM and BS observed is not expected to have a clinical impact, but future clinical studies are warranted.
- Published
- 2023
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19. Biomechanical performance of a novel light-curable bone fixation technique.
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Schwarzenberg P, Colding-Rasmussen T, Hutchinson DJ, Mischler D, Horstmann P, Petersen MM, Jacobsen S, Pastor T, Malkoch M, Wong C, and Varga P
- Subjects
- Animals, Sheep, Tissue Adhesions, Bone Plates, Osteotomy, Biomechanical Phenomena, Fracture Fixation, Internal methods, Osteoporotic Fractures
- Abstract
Traumatic bone fractures are often debilitating injuries that may require surgical fixation to ensure sufficient healing. Currently, the most frequently used osteosynthesis materials are metal-based; however, in certain cases, such as complex comminuted osteoporotic fractures, they may not provide the best solution due to their rigid and non-customizable nature. In phalanx fractures in particular, metal plates have been shown to induce joint stiffness and soft tissue adhesions. A new osteosynthesis method using a light curable polymer composite has been developed. This method has demonstrated itself to be a versatile solution that can be shaped by surgeons in situ and has been shown to induce no soft tissue adhesions. In this study, the biomechanical performance of AdhFix was compared to conventional metal plates. The osteosyntheses were tested in seven different groups with varying loading modality (bending and torsion), osteotomy gap size, and fixation type and size in a sheep phalanx model. AdhFix demonstrated statistically higher stiffnesses in torsion (64.64 ± 9.27 and 114.08 ± 20.98 Nmm/° vs. 33.88 ± 3.10 Nmm/°) and in reduced fractures in bending (13.70 ± 2.75 Nm/mm vs. 8.69 ± 1.16 Nmm/°), while the metal plates were stiffer in unreduced fractures (7.44 ± 1.75 Nm/mm vs. 2.70 ± 0.72 Nmm/°). The metal plates withstood equivalent or significantly higher torques in torsion (534.28 ± 25.74 Nmm vs. 614.10 ± 118.44 and 414.82 ± 70.98 Nmm) and significantly higher bending moments (19.51 ± 2.24 and 22.72 ± 2.68 Nm vs. 5.38 ± 0.73 and 1.22 ± 0.30 Nm). This study illustrated that the AdhFix platform is a viable, customizable solution that is comparable to the mechanical properties of traditional metal plates within the range of physiological loading values reported in literature., (© 2023. The Author(s).)
- Published
- 2023
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20. Placenta Powder-Infused Thiol-Ene PEG Hydrogels as Potential Tissue Engineering Scaffolds.
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Fan Y, Lüchow M, Badria A, Hutchinson DJ, and Malkoch M
- Subjects
- Humans, Animals, Mice, Powders, Tissue Scaffolds chemistry, Biocompatible Materials pharmacology, Polyethylene Glycols chemistry, Hydrogels pharmacology, Hydrogels chemistry, Tissue Engineering methods, Sulfhydryl Compounds
- Abstract
Human placenta is a source of extracellular matrix for tissue engineering. In this study, placenta powder (PP), made from decellularized human placenta, was physically incorporated into synthetic poly(ethylene glycol) (PEG)-based hydrogels via UV-initiated thiol-ene coupling (TEC). The PP-incorporated PEG hydrogels (MoDPEG+) showed tunable storage moduli ranging from 1080 ± 290 to 51,400 ± 200 Pa. The addition of PP (1, 4, or 8 wt %) within the PEG hydrogels increased the storage moduli, with the 8 wt % PP hydrogels showing the highest storage moduli. PP reduced the swelling ratios compared with the pristine hydrogels (MoDPEG). All hydrogels showed good biocompatibility in vitro toward human skin cells and murine macrophages, with cell viability above 91%. Importantly, cells could adhere and proliferate on MoDPEG+ hydrogels due to the bioactive PP, while MoDPEG hydrogels were bio-inert as cells moved away from the hydrogel or were distributed in a large cluster on the hydrogel surface. To showcase their potential use in application-driven research, the MoDPEG+ hydrogels were straightforwardly (i) 3D printed using the SLA technique and (ii) produced via high-energy visible light (HEV-TEC) to populate damaged soft-tissue or bone cavities. Taking advantage of the bioactivity of PP and the tunable physicochemical properties of the synthetic PEG hydrogels, the presented MoDPEG+ hydrogels show great promise for tissue regeneration.
- Published
- 2023
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21. Dendritic Nanogels Directed Dual-Encapsulation Topical Delivery System of Antimicrobial Peptides Targeting Skin Infections.
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Zhang Y, Håkansson J, Fan Y, Andrén OCJ, San Jacinto García J, Qin L, Umerska A, Hutchinson DJ, Lüchow M, Mahlapuu M, and Malkoch M
- Subjects
- Mice, Humans, Animals, Swine, Nanogels, Staphylococcus aureus, Poloxamer, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Gels, Microbial Sensitivity Tests, Antimicrobial Peptides, Antimicrobial Cationic Peptides pharmacology
- Abstract
Antimicrobial peptides (AMPs) are promising antibacterial agents in the fight against multidrug resistant pathogens. However, their application to skin infections is limited by the absence of a realizable topical delivery strategy. Herein, a hybrid hierarchical delivery system for topical delivery of AMPs is accomplished through the incorporation of AMPs into dendritic nanogels (DNGs) and their subsequent embedding into poloxamer gel. The high level of control over the crosslink density and the number of chosen functionalities makes DNGs ideal capsules with tunable loading capacity for DPK-060, a human kininogen-derived AMP. Once embedded into the poloxamer gel, DPK-060 encapsulated in DNGs displays a slower release rate compared to those entrapped directly in the gels. In vitro EpiDerm Skin Irritation Tests show good biocompatibility, while MIC and time-kill curves reveal the potency of the peptide toward Staphylococcus aureus. Anti-infection tests on ex vivo pig skin and in vivo mouse infection models demonstrate that formulations with 0.5% and 1% AMPs significantly inhibit the growth of S. aureus. Similar outcomes are observed for an in vivo mouse surgical site infection model. Importantly, when normalizing the bacteria inhibition to released/free DPK-060 at the wound site, all formulations display superior efficacy compared to DPK-060 in solution., (© 2023 The Authors. Macromolecular Bioscience published by Wiley-VCH GmbH.)
- Published
- 2023
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22. Soft Hydroxyapatite Composites Based on Triazine-Trione Systems as Potential Biomedical Engineering Frameworks.
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Lin J, Fan Y, Hutchinson DJ, and Malkoch M
- Subjects
- Triazines chemistry, Stress, Mechanical, Pliability, Composite Resins chemistry, Sulfhydryl Compounds chemistry, Hydroxyapatites, Materials Testing, Methacrylates chemistry, Biomedical Engineering
- Abstract
Composites of triazine-trione (TATO) thiol-ene networks and hydroxyapatite (HA) have shown great potential as topological fixation materials for complex bone fractures due to their high flexural modulus, biocompatibility, and insusceptibility to forming soft-tissue adhesions. However, the rigid mechanical properties of these composites make them unsuitable for applications requiring softness. The scope of these materials could therefore be widened by the design of new TATO monomers that would lead to composites with a range of mechanical properties. In this work, four novel TATO-based monomers, decorated with either ester or amide linkages as well as alkene or alkyne end groups, have been proposed and synthesized via fluoride-promoted esterification (FPE) chemistry. The ester-modified monomers were then successfully formulated along with the thiol TATO monomer tris [2-(3-mercaptopropionyloxy)ethyl] isocyanurate (TEMPIC) and HA to give soft composites, following the established photo-initiated thiol-ene coupling (TEC) or thiol-yne coupling (TYC) chemistry methodologies. The most promising composite shows excellent softness, with a flexural modulus of 57 (2) MPa and ε
f at maximum σf of 11.8 (0.3)%, which are 117 and 10 times softer than the previously developed system containing the commercially available tri-allyl TATO monomer (TATATO). Meanwhile, the surgically convenient viscosity of the composite resins and their excellent cytotoxicity profile allow them to be used in the construction of soft objects in a variety of shapes through drop-casting suitable for biomedical applications.- Published
- 2023
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23. Enoxaparin Reduces Catheter-associated Venous Thrombosis After Infant Cardiac Surgery.
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Swartz MF, Hutchinson DJ, Stauber SD, Taillie ER, Alfieris GM, and Cholette JM
- Subjects
- Anticoagulants therapeutic use, Catheters, Child, Enoxaparin therapeutic use, Hemorrhage, Humans, Infant, Cardiac Surgical Procedures adverse effects, Venous Thrombosis drug therapy, Venous Thrombosis etiology, Venous Thrombosis prevention & control
- Abstract
Background: Central venous catheter (CVC) related venous thrombosis (VT) after pediatric cardiac surgery increases morbidity and mortality. Although VT prevention using low-dose anticoagulation therapy has proven ineffective, anticoagulation therapy using high-dose enoxaparin to achieve a therapeutic anti-Xa level has not been studied. We hypothesized that high-dose enoxaparin would reduce VT after pediatric cardiac surgery., Methods: Enoxaparin was administered to infants aged less than 150 days when postoperative CVC duration was anticipated to extend beyond 5 days. The primary outcome was the rate of VT, reexploration for bleeding, and postoperative red blood cell transfusions per 1000 CVC days., Results: From 2012 to 2019, 157 infants were treated with enoxaparin. Infants were divided into two groups: (1) subtherapeutic (n = 51), in which therapeutic anti-Xa level (0.5 to 1.0 IU/mL) was not achieved; and (2) therapeutic (n = 106), in which therapeutic anti-Xa level was achieved. Baseline demographics demonstrated a lower age at operation in the therapeutic group. The subtherapeutic group had a higher VT rate per 1000 CVC days (8.2) compared with the therapeutic group (2.6; P = .005). Reexploration for bleeding was similar between groups. The number of postoperative red blood cell transfusions per 1000 CVC days was significantly greater in the subtherapeutic group (109.4 vs 81.6; P = .008). Multivariate analysis demonstrated that higher median anti-Xa levels reduced the risk of VT (odds ratio 0.02; 95% confidence interval, 0.001 to 0.63; P = .02)., Conclusions: These data suggest that enoxaparin treatment resulting in a therapeutic anti-Xa level reduces postoperative CVC-associated VT without increasing bleeding complications., (Copyright © 2022 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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24. The Rochester Relapse Risk Scale: Developing a Standardized Approach to Predicting Substance Relapse in Liver Transplant Candidates.
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Leistman SC, Melaragno JI, Dokus MK, Martens JA, Salter MA, Hutchinson DJ, Hernandez-Alejandro R, Al-Judaibi B, and Nickels MW
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Prospective Studies, Recurrence, Reproducibility of Results, Retrospective Studies, Risk Factors, Treatment Outcome, Liver Transplantation adverse effects
- Abstract
Objectives: Substance abuse is a risk factor for nonadherence and graft failure after orthotopic liver transplant. This study aimed to evaluate the ability of an internally developed tool, the Rochester Relapse Risk Scale, to predict substance relapse in liver transplant candidates., Materials and Methods: This single-center, retrospective, observational study included adult patients evaluated for orthotopic liver transplant using the Rochester Relapse Risk Scale. Primary outcome was rate of substance relapse, as measured by the risk scale, which stratified patients into relapse risk levels based on the number of factors present., Results: In total, 303 patients (71.6% men, 90.4% White, median age of 55 years [interquartile range, 49-60 y]) were included. Median follow-up time was 212 days (interquartile range, 73-661 d). Seventy-four patients (24.4%) relapsed at 127 days (interquartile range, 55-461 d) after evaluation, with 60.8% who relapsed within 6 months. Relapse rates correlated with assigned risk level, with 8.3% relapsing at low, 19.0% at low-moderate, 25.3% at moderate, 33.8% at moderate-high, and 40.0% at high risk. High-risk cohorts had significantly shorter median time to relapse versus low-risk cohorts (104 vs 154 days; P = .001)., Conclusions: Assignment of relapse risk level according to the Rochester Relapse Risk Scale aligned with rates of relapse. Additional studies are needed to refine the tool, assess inter-rater reliability, and confirm findings in prospective, multicenter studies.
- Published
- 2021
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25. Escalation in Therapy Based on Intravenous Magnesium Sulfate Dosing in Pediatric Patients With Asthma Exacerbations.
- Author
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Kapuscinski CA, Stauber SD, and Hutchinson DJ
- Abstract
Objective: Our objective was to compare doses of intravenous magnesium sulfate and their association with escalations in therapy in children and adolescents presenting to the emergency department with an asthma exacerbation., Methods: This was a retrospective cohort study among children who received both magnesium sulfate and standard of care therapy for asthma exacerbations. A classification and regression tree (CART) analysis was performed to identify a breakpoint in dose in which a difference in the primary outcome was present. The primary endpoint was need for escalation in therapy within 24 hours of initial magnesium sulfate dose, defined as need for invasive or non-invasive mechanical ventilation or need for adjunctive therapy, that is, epinephrine, terbutaline, aminophylline, theophylline, ketamine, heliox, or additional doses of magnesium sulfate., Results: A total of 210 patients were included in the study. A CART analysis identified that a breakpoint of 27 mg/kg of magnesium was associated with a difference in the primary outcome of escalation in therapy in patients <40 kg. A subgroup analysis of patients <40 kg (n = 149) found patients who received magnesium doses >27 mg/kg had a higher incidence of the primary outcome of escalation in therapy, 15 patients (18.3%) versus 3 patients (4.5%) in the ≤27-mg/kg/dose group (p = 0.011)., Conclusions: Our results demonstrate larger doses of magnesium sulfate are associated with an increased need for invasive or non-invasive mechanical ventilation or need for adjunctive therapy(ies). Our findings are limited by confounding factors that may have influenced this outcome in our population., Competing Interests: Disclosure The authors declare no conflicts or financial interest in any product or service mentioned in the manuscript, including grants, equipment, medications, employment, gifts, and honoraria. The authors had full access to all the data and take responsibility for the integrity and accuracy of the data analysis., (Copyright Pediatric Pharmacy Association. All rights reserved. For permissions, email: mhelms@pediatricpharmacy.org 2020.)
- Published
- 2020
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26. Stability of Extemporaneously Prepared Sodium Benzoate Oral Suspension.
- Author
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Atkins JR, Lull ME, Decker AS, and Hutchinson DJ
- Subjects
- Administration, Oral, Drug Stability, Suspensions, Sodium Benzoate chemistry
- Abstract
The stability of extemporaneously prepared sodium benzoate oral suspension in cherry syrup and Ora-Sweet was studied. Oral solutions of 250-mg/mL sodium benzoate were prepared in either cherry syrup or Ora-Sweet. To a beaker, 50 grams of Sodium Benzoate Powder USP was dissolved and filtered, the solution was divided equally into two parts, and each aliquot was added into two separate calibrated 100-mL amber vials. In the first vial, cherry syrup was added to make a final volume of 100 mL. In the second vial, Ora-Sweet was added to give a final volume of 100 mL. This process was repeated to prepare three solutions of each kind and all were stored at room temperature. A 250-µL sample was withdrawn immediately after preparation and again at 7, 14, 28, 60, and 90 days for each sample. At each time point, further dilution was made to an expected concentration of 0.25 mg/mL with sample diluent, and the samples were assayed in triplicate by stability-indicating high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration. At least 92% of the initial concentration of sodium benzoate in cherry syrup and at least 96% of the sodium benzoate in Ora-Sweet remained throughout the 90-day study period. There were no detectable changes in color and no visible microbial growth in any sample. Extemporaneously compounded suspensions of sodium benzoate in cherry syrup or Ora-Sweet were stable for at least 90 days when stored in a 4-oz amber plastic bottle at room temperature in reduced lighting., (Copyright© by International Journal of Pharmaceutical Compounding, Inc.)
- Published
- 2018
27. Stability of extemporaneously prepared cinacalcet oral suspensions.
- Author
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Thomson K, Hutchinson DJ, and Chablani L
- Subjects
- Administration, Oral, Calcimimetic Agents chemistry, Chromatography, High Pressure Liquid methods, Cinacalcet chemistry, Drug Packaging, Drug Stability, Drug Storage, Pharmaceutical Vehicles chemistry, Polypropylenes chemistry, Refrigeration, Suspensions, Time Factors, Calcimimetic Agents administration & dosage, Chemistry, Pharmaceutical methods, Cinacalcet administration & dosage, Drug Compounding methods
- Abstract
Purpose: The stability of extemporaneously prepared cinacalcet suspensions over 90 days was evaluated., Methods: Cinacalcet 5-mg/mL suspension was prepared by triturating 30-mg cinacalcet tablets. Twelve 30-mL batches were prepared with a 1:1 mixture of Ora-Plus and either Ora-Sweet or Ora-Sweet SF (sugar free). Three suspensions of each kind were stored at both room temperature and refrigerated conditions. A 1-mL sample was taken from each bottle at 0, 7, 18, 32, 64, and 90 days. Each sample was assayed using high-performance liquid chromatography (HPLC). A new HPLC method for evaluating drug peaks of pure cinacalcet was developed. Stability was defined as retention of at least 90% of the initial drug concentration., Results: The HPLC method established in this study serves as a novel assay for evaluating cinacalcet oral suspensions. For all suspensions tested at individual conditions, the concentration remained above 90% of the initial concentration for 90 days of storage with the exception of Ora-Plus and Ora-Sweet SF suspensions stored under refrigeration, which were stable for 64 days. Usual sedimentation of the suspensions occurred over time but resolved with agitation; there was no other change in visual appearance of the suspensions over the course of the 90-day study. The color and odor of the suspensions throughout the study remained unchanged with respect to the initial time point., Conclusion: Extemporaneously compounded cinacalcet 5-mg/mL oral suspensions prepared with a 1:1 mixture of Ora-Plus and either Ora-Sweet or Ora-Sweet SF and stored in 2-oz amber polypropylene plastic bottles were stable for at least 64 days at room temperature and under refrigeration., (Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.)
- Published
- 2018
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28. Supramolecular self-assembly of heterobimetallic complexes: a new N,P-based, selective heteroditopic ligand.
- Author
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Hutchinson DJ, Clauss R, Sárosi MB, and Hey-Hawkins E
- Abstract
Pyrimidine-hydrazone and phosphole architectures have been combined to create a new heteroditopic ligand capable of forming heterobimetallic Zn
II /PdII , PbII /PdII and CuII /PdII complexes in high yielding stepwise or one pot reactions. The catalytic activity of these complexes in Heck coupling and Miyaura borylation reactions was investigated.- Published
- 2018
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29. Methadone and Corrected QT Prolongation in Pain and Palliative Care Patients: A Case-Control Study.
- Author
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Juba KM, Khadem TM, Hutchinson DJ, and Brown JE
- Subjects
- Adult, Aged, Aged, 80 and over, Case-Control Studies, Dose-Response Relationship, Drug, Female, Humans, Male, Middle Aged, Palliative Care methods, Risk Factors, Analgesics, Opioid adverse effects, Analgesics, Opioid therapeutic use, Cancer Pain drug therapy, Long QT Syndrome chemically induced, Methadone therapeutic use, Neoplasms complications, Opiate Substitution Treatment
- Abstract
Background: Methadone (ME) is commonly used in pain and palliative care (PPC) patients with refractory pain or intolerable opioid adverse effects (AEs). A unique ME AE is its corrected QT (QTc) interval prolongation risk, but most evidence exists in methadone maintenance therapy patients., Objective: Our goal was to identify QTc interval prolongation risk factors in PPC patients receiving ME and other medications known to prolong the QTc interval and develop a risk stratification tool., Design: We performed a case-control study of adult inpatients receiving ME for pain management. Settings/Subjects: Adult inpatients receiving ME with a QTc >470 msec (males) and >480 msec (females) were matched 1:2 according to age, history of QTc prolongation, and gender with ME patients who did not have a prolonged QTc interval. QTc prolongation risk factors were collected for both groups. Covariates were analyzed using conditional logistic regression. Classification and regression tree analysis was used to identify the ME dose associated with QTc prolongation., Results: Predictors of QTc prolongation included congestive heart failure (CHF) (OR: 11.9; 95% CI: 3.7-38.2; p < 0.00), peptic ulcer disease (PUD) (odds ratio [OR]: 8.3; 95% confidence interval [95% CI]: 2.4-28.9; p < 0.00), hypokalemia (OR: 6.5; 95% CI: 1.5-28.2; p < 0.01), rheumatologic diseases (OR: 4.7; 95% CI: 1.6-13.9; p < 0.00), taking medications with a known torsades de pointes (TdP) risk (OR: 4.4; 95% CI: 1.8-10.7; p < 0.01), malignancy (OR: 3.3; 95% CI: 1.2-9.3; p < 0.03), hypocalcemia (OR: 2.1; 95% CI: 0.9-4.8; p < 0.07), and ME doses >45 mg per day (OR: 1.9; 95% CI: 0.8-4.8; p < 0.16). Mild liver disease was protective against QTc prolongation (OR: 0.05; 95% CI: 0.0-0.46; p < 0.01)., Conclusions: Predictors of QTc prolongation in our multivariate conditional logistic regression model included CHF, PUD, hypokalemia, rheumatologic disorders, use of medications with a known TdP risk, malignancy, hypocalcemia, and ME doses >45 mg per day.
- Published
- 2017
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30. Tetratopic pyrimidine-hydrazone ligands modified with terminal hydroxymethyl and acryloyl arms and their Pb(II), Zn(II), Cu(II) and Ag(I) complexes.
- Author
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Hutchinson DJ, Hanton LR, and Moratti SC
- Abstract
The first tetratopic pyrimidine-hydrazone (pym-hyz) molecular strands containing terminal hydroxymethyl (L1) and acryloyl (L2) functional groups have been synthesised. L1 was produced by step-wise imine condensation reactions, starting with 6-hydroxymethyl-2-pyridinecarboxaldehyde. L2 was then synthesised through the treatment of L1 with acryloyl chloride. NMR spectroscopy and X-ray crystallography showed that the ligands adopted a helical shape, comprised of 1 and 1/3 helical turns. Both L1 and L2 uncoiled upon reaction with an excess amount of Pb(II), Zn(II) and Cu(II) ions, resulting in linear M4LA8 complexes (where M = Pb(II), Zn(II), or Cu(II); L = L1 or L2; and A = ClO4(-), SO3CF3(-) or BF4(-)). Horse-shoe shaped Pb2LA4 complexes were also formed by reacting Pb(II) ions with either L1 or L2 in a 2 : 1 metal to ligand ratio. The addition of Ag(I) ions to either L1 or L2 resulted in Ag2L2A2 double helicates, which were stable in the presence of excess Ag(I). The Pb(II), Zn(II) and Ag(I) complexes were characterised by NMR spectroscopy, while UV-Vis spectroscopy was used to probe the Cu(II) complexes. In addition, X-ray crystallography was used to analyse the linear Pb4L1A8, horse-shoe shaped Pb2L1(ClO4)4, twisted Cu3L2(SO3CF3)6, and double helicate Ag2L12(SO3CF3)2 complexes yielding the structures [Pb4L1(ClO4)7(H2O)]ClO4·4CH3NO2 (1), [Pb4L1(SO3CF3)8]2·6CH3CN·H2O (2), [Pb2L1(ClO4)2(CH3CN)(H2O)](ClO4)2·2CH3CN·C4H10O·H2O (3), [Cu3L2(SO3CF3)3(CH3CN)2(H2O)](SO3CF3)3·2CH3CN·H2O (4) and [Ag2L12](SO3CF3)2·CH3CN·H2O (5), respectively.
- Published
- 2014
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31. Education in pediatrics in US colleges and schools of pharmacy.
- Author
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Prescott WA Jr, Dahl EM, and Hutchinson DJ
- Subjects
- Curriculum, Humans, Internet, Surveys and Questionnaires, Teaching methods, United States, Education, Pharmacy methods, Pediatrics education, Schools, Pharmacy
- Abstract
Objective: To determine the extent to which pediatrics is taught at US doctor of pharmacy (PharmD) programs and to characterize what is being taught and how., Methods: A 40-question online survey instrument was sent to accredited and candidate-status US PharmD programs., Results: Of 86 participating programs (67.2% response rate), 81 (94.2%) indicated that pediatric topics were included in their required classroom curricula (mean, 21.9 contact hours). A pediatric elective course was offered by 61.0% of programs (mean, 25.9 contact hours). Advanced pharmacy practice experiences (APPEs) in pediatrics were offered by 97.4% of programs, with an average of 27 students per program completing this practice experience annually., Conclusions: Almost all responding programs incorporated pediatrics in their required curricula. Pediatric elective courses provided an adequate mean number of contact hours, but 39.0% of programs did not offer an elective course. One-fifth of students completed a pediatric APPE prior to graduation. Continued expansion of pediatric-focused classroom and experiential curricula across US PharmD programs is recommended.
- Published
- 2014
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32. Metal-induced isomerization of a molecular strand containing contradictory dynamic coordination sites.
- Author
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Hutchinson DJ, James MP, Hanton LR, and Moratti SC
- Abstract
A new hydroxymethyl terminated pyrimidine-hydrazone (pym-hyz) ligand (L1) was synthesized with a central hyz-pyridine-hyz (hyz-py-hyz) motif replacing the usual hyz-pym-hyz unit, to create a molecular strand that underwent metal-induced isomerization with a minimal net change in ligand length. NMR spectroscopy showed that L1 had a horseshoe shape due to the hyz-py-hyz and pym-hyz bonds adopting transoid conformations. The ligand was successfully reacted with Pb(II), Zn(II), and Ag(I) salts in either CH3CN or CH3NO2 resulting in horseshoe-shaped M(n+)3L1A3n (where A = ClO4(-) or SO3CF3(-)) complexes in the solution phase. Crystals were grown from these solutions, the structures of which were highly dependent on the metal ion and solvent used, and were distinctly different from those seen in solution. The crystals grown from mixtures of Pb(ClO4)2·3H2O and L1 in either CH3CN or CH3NO2 resulted in the horseshoe-shaped [Pb3L1(ClO4)4(H2O)2](ClO4)2·CH3CN (1) complex or the {[Pb3L1(ClO4)4(H2O)](ClO4)2}∞·CH3NO2 (2) helical coordination polymer, respectively. The horseshoe-shaped [Pb3L1(SO3CF3)6]·CH3CN (3) complex was crystallized from a solution of Pb(SO3CF3)2·H2O and L1 in CH3CN, while the crystals grown from the solution of Zn(SO3CF3)2 and L1 in CH3CN consisted of the zigzag-shaped [Zn3L1(H2O)7](SO3CF3)6 (4) complex. The [Ag3(L1)2](SO3CF3)3 (5) double-helicate and the macrocycle-like [Ag6(L1)2](SO3CF3)6 (6) complex were crystallized from solutions of AgSO3CF3 and L1 in either CH3CN or CH3NO2, respectively.
- Published
- 2014
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33. Influence of terminal acryloyl arms on the coordination chemistry of a ditopic pyrimidine-hydrazone ligand: comparison of Pb(II), Zn(II), Cu(II), and Ag(I) complexes.
- Author
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Hutchinson DJ, Hanton LR, and Moratti SC
- Subjects
- Copper chemistry, Crystallography, X-Ray, Lead chemistry, Ligands, Models, Molecular, Molecular Structure, Organometallic Compounds chemical synthesis, Silver chemistry, Zinc chemistry, Hydrazones chemistry, Organometallic Compounds chemistry, Pyrimidines chemistry
- Abstract
A new ditopic pyrimidine-hydrazone ligand, 6-hydroxymethylacryloyl-2-pyridinecarboxaldehyde, 2,2'-[2,2'-(2-methyl-4,6-pyrimidinediyl)bis(1-methylhydrazone)] (L2), was synthesized with terminal acryloyl functional groups to allow incorporation into copolymer gel actuators. NMR spectroscopy was used to show that L2 adopted a horseshoe shape with transoid-transoid pym-hyz-py linkages. Metal complexation studies were performed with L2 and salts of Pb(II), Zn(II), Cu(II), and Ag(I) ions in CH3CN in a variety of metal to ligand ratios. Reacting L2 with an excess amount of any of the metal ions resulted in linear complexes where the pym-hyz-py linkages were rotated to a cisoid-cisoid conformation. NMR spectroscopy showed that the acryloyl arms of L2 did not interact with the bound metal ions in solution. Seven of the linear complexes (1-7) were crystallized and analyzed by X-ray diffraction. Most of these complexes (4-7) also showed no coordination between the acryloyl arms and the metal ions; however, complexes 1-3 showed some interactions. Both of the acryloyl arms were coordinated to Pb(II) ions in [Pb2L2(SO3CF3)4] (1), one through the carbonyl oxygen donor and the other through the alkoxy oxygen donor. One of the acryloyl arms of [Cu2L2(CH3CN)3](SO3CF3)4 (2) was coordinated to one of the Cu(II) ions through the carbonyl oxygen donor. There appeared to be a weak association between the alkoxy donors of the acryloyl arms and the Pb(II) ions of [Pb2L2(ClO4)4]·CH3CN (3). Reaction of excess AgSO3CF3 with L2 was repeated in CD3NO2, resulting in crystals of {[Ag7(L2)2(SO3CF3)6(H2O)2] SO3CF3}∞ (8), the polymeric structure of which resulted from coordination between the carbonyl donors of the acryloyl arms and the Ag(I) ions. In all cases the coordination and steric effects of the acryloyl arms did not inhibit isomerization of the pym-hyz bonds of L2 or the core shape of the linear complexes.
- Published
- 2013
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34. Sensitivity of silver(I) complexes of a pyrimidine-hydrazone ligand to solvent, counteranion, and metal-to-ligand ratio changes.
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Hutchinson DJ, Cameron SA, Hanton LR, and Moratti SC
- Subjects
- Ligands, Models, Molecular, Molecular Conformation, Organometallic Compounds chemical synthesis, Solutions, Hydrazones chemistry, Organometallic Compounds chemistry, Pyrimidines chemistry, Silver chemistry, Solvents chemistry
- Abstract
Metal complexation studies were performed with AgSO(3)CF(3) and AgBF(4) and the ditopic pyrimidine-hydrazone ligand 6-(hydroxymethyl)pyridine-2-carboxaldehyde (2-methylpyrimidine-4,6-diyl)bis(1-methylhydrazone) (1) in both CH(3)CN and CH(3)NO(2) in a variety of metal-to-ligand ratios. The resulting complexes were studied in solution by NMR spectroscopy and in the solid state by X-ray crystallography. Reacting either AgSO(3)CF(3) or AgBF(4) with 1 in either CH(3)CN or CH(3)NO(2) in a 1:1 metal-to-ligand ratio produced a double helicate in solution. This double helicate could be converted into a linear complex by increasing the metal-to-ligand ratio; however, the degree of conversion depended on the solvent and counteranion used. Attempts to crystallize the linear AgSO(3)CF(3) complex resulted in crystals with the dimeric structure [Ag(2)1(CH(3)CN)(2)](2)(SO(3)CF(3))(4) (2), while attempts to crystallize the AgSO(3)CF(3) double helicate from CH(3)CN resulted in crystals of another dimeric complex, [Ag(2)1(SO(3)CF(3))(CH(3)CN)(2)](2)(SO(3)CF(3))(2)·H(2)O (3). The AgSO(3)CF(3) double helicate was successfully crystallized from a mixture of CH(3)CN and CH(3)NO(2) and had the structure [Ag(2)1(2)](SO(3)CF(3))(2)·3CH(3)NO(2) (4). The linear AgBF(4) complex could not be isolated from the double helicate in solution; however, crystals grown from a solution containing both the AgBF(4) double helicate and linear complexes in CH(3)CN had the structure [Ag(2)1(CH(3)CN)(2)](BF(4))(2) (5). The AgBF(4) double helicate could only be crystallized from CH(3)NO(2) and had the structure [Ag(2)1(2)](BF(4))(2)·2CH(3)NO(2) (6).
- Published
- 2012
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35. Monocarboxylate Transporter Inhibition with Osmotic Diuresis Increases γ-Hydroxybutyrate Renal Elimination in Humans: A Proof-of-Concept Study.
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Morris ME, Morse BL, Baciewicz GJ, Tessena MM, Acquisto NM, Hutchinson DJ, and Dicenzo R
- Abstract
Background and Objective: The purpose of the current study was to demonstrate proof-of-concept that monocarboxylate transporter (MCT) inhibition with L-lactate combined with osmotic diuresis increases renal clearance of γ-hydroxybutyrate (GHB) in human subjects. GHB is a substrate for human and rodent MCTs, which are responsible for GHB renal reabsorption, and this therapy increases GHB renal clearance in rats., Methods: Ten healthy volunteers were administered GHB orally as sodium oxybate 50 mg/kg (4.5 gm maximum dose) on two different study days. On study day 1, GHB was administered alone. On study day 2, treatment of L-lactate 0.125 mmol/kg and mannitol 200 mg/kg followed by L-lactate 0.75 mmol/kg/hr was administered intravenously 30 minutes after GHB ingestion. Blood and urine were collected for 6 hours, analyzed for GHB, and pharmacokinetic and statistical analyses performed., Results: L-lactate/mannitol administration significantly increased GHB renal clearance compared to GHB alone, 439 vs. 615 mL/hr (P=0.001), and increased the percentage of GHB dose excreted in the urine, 2.2 vs. 3.3% (P=0.021). Total clearance was unchanged., Conclusions: MCT inhibition with L-lactate combined with osmotic diuresis increases GHB renal elimination in humans. No effect on total clearance was observed in this study due to the negligible contribution of renal clearance to total clearance at this low GHB dose. Considering the nonlinear renal elimination of GHB, further research in overdose cases is warranted to assess the efficacy of this treatment strategy for increasing renal and total clearance at high GHB doses.
- Published
- 2011
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36. Stability of diluted adenosine solutions in polyvinyl chloride infusion bags.
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Kaltenbach M, Hutchinson DJ, Bollinger JE, and Zhao F
- Subjects
- Chromatography, High Pressure Liquid, Drug Packaging, Drug Stability, Drug Storage, Glucose chemistry, Hydrogen-Ion Concentration, Infusions, Intravenous, Pharmaceutical Solutions, Refrigeration, Temperature, Time Factors, Adenosine chemistry, Polyvinyl Chloride chemistry, Sodium Chloride chemistry, Vasodilator Agents chemistry
- Abstract
Purpose: The stability of diluted adenosine solutions in polyvinyl chloride infusion bags was studied., Methods: Adenosine 50-, 100-, and 220-μg/mL solutions were prepared in 50-mL polyvinyl chloride (PVC) infusion bags containing 0.9% sodium chloride injection or 5% dextrose injection and stored at room temperature (23-25 °C) or under refrigeration (2-8 °C). Each sample of every combination of concentration, diluent, and storage temperature was prepared in triplicate, yielding 36 samples. The samples were assayed using a stability-indicating, reverse-phase high-performance liquid chromatographic method immediately after preparation (time zero) and at 24 hours, 48 hours, 7 days, and 14 days. pH was measured at time zero, 48 hours, 7 days, and 14 days. Time zero concentrations were calculated from the equation produced from a calibration curve of standards ranging from 10 to 500 μg/mL. Samples were also visually inspected against a light background for clarity, color, and the presence of crystalline particulate matter. Stability was defined as retaining at least 90% of the initial adenosine concentration., Results: After 14 days, all samples retained greater than 98% of the initial adenosine concentration, with no evidence of adsorption, visible precipitation, or considerable change in pH, suggesting minimal to no loss of product due to degradation or adsorption., Conclusion: Adenosine 50-, 100-, and 220-μg/mL solutions in 50-mL PVC infusion bags containing 0.9% sodium chloride injection or 5% dextrose injection stored at room temperature and refrigerated conditions were stable for at least 14 days.
- Published
- 2011
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37. Metal ion-controlled self-assembly using pyrimidine hydrazone molecular strands with terminal hydroxymethyl groups: a comparison of Pb(II) and Zn(II) complexes.
- Author
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Hutchinson DJ, Hanton LR, and Moratti SC
- Abstract
Metal complexation studies were performed with the ditopic pyrimidine-hydrazone (pym-hyz) strand 6-hydroxymethylpyridine-2-carboxaldehyde (2-methyl-pyrimidine-4,6-diyl)bis(1-methylhydrazone) (1) and Pb(ClO(4))(2)·3H(2)O, Pb(SO(3)CF(3))(2)·H(2)O, Zn(SO(3)CF(3))(2), and Zn(BF(4))(2) to examine the ability of 1 to form various supramolecular architectures. X-ray crystallographic and NMR studies showed that coordination of the Pb(II) salts with 1 on a 2:1 metal/ligand ratio in CH(3)CN and CH(3)NO(2) resulted in the linear complexes [Pb(2)1(ClO(4))(4)] (2), [Pb(2)1(ClO(4))(3)(H(2)O)]ClO(4) (3), and [Pb(2)1(SO(3)CF(3))(3)(H(2)O)]SO(3)CF(3) (4). Two unusually distorted [2 × 2] grid complexes, [Pb1(ClO(4))](4)(ClO(4))(4) (5) and [Pb1(ClO(4))](4)(ClO(4))(4)·4CH(3)NO(2) (6), were formed by reacting Pb(ClO(4))(2)·6H(2)O and 1 on a 1:1 metal/ligand ratio in CH(3)CN and CH(3)NO(2). These grids formed despite coordination of the hydroxymethyl arms due to the large, flexible coordination sphere of the Pb(II) ions. A [2 × 2] grid complex was formed in solution by reacting Pb(SO(3)CF(3))(2)·H(2)O and 1 on a 1:1 metal/ligand ratio in CH(3)CN as shown by (1)H NMR, microanalysis, and ESMS. Reacting the Zn(II) salts with 1 on a 2:1 metal/ligand ratio gave the linear complexes [Zn(2)1(H(2)O)(4)](SO(3)CF(3))(4)·C(2)H(5)O (7) and [Zn(2)1(BF(4))(H(2)O)(2)(CH(3)CN)](BF(4))(3)·H(2)O (8). (1)H NMR studies showed the Zn(II) and Pb(II) ions in these linear complexes were labile undergoing metal ion exchange. All of the complexes exhibited pym-hyz linkages in their cisoid conformation and binding between the hydroxymethyl arms and the metal ions. No complexes were isolated from reacting either of the Zn(II) salts with 1 on a 1:1 metal/ligand ratio, due to the smaller size of the Zn(II) coordination sphere as compared to the much larger Pb(II) ions., (© 2011 American Chemical Society)
- Published
- 2011
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38. Respiratory Syncytial Virus Prophylaxis in Special Populations: Is it Something Worth Considering in Cystic Fibrosis and Immunosuppression?
- Author
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Prescott WA Jr and Hutchinson DJ
- Abstract
Respiratory syncytial virus (RSV) bronchiolitis is the leading cause of infant hospitalization in the United States. Prophylaxis with palivizumab is effective in reducing RSV hospitalizations in premature infants and in infants or children with chronic lung disease or congenital heart disease. Patients with CF or those who are immunocompromised may be at increased risk for RSV infection-related complications; hence, prophylaxis may prove beneficial to these populations. The extent of palivizumab use in the CF and immunocompromised populations is variable. Palivizumab appears to be safe and may be effective in infants and young children with CF and immunocompromise. However, well-designed, randomized, controlled trials published in peer-reviewed journals are lacking, and its routine use can therefore not be recommended at this time. If used in patients with CF or those who are immunocompromised, RSV prophylaxis should be restricted to peak outbreak months in order to optimize the cost benefit of palivizumab.
- Published
- 2011
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39. Control of self-assembly through the influence of terminal hydroxymethyl groups on the metal coordination of pyrimidine-hydrazone Cu(II) complexes.
- Author
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Hutchinson DJ, Hanton LR, and Moratti SC
- Abstract
The synthesis and characterization of 6-hydroxymethylpyridine-2-carboxaldehyde (2-methyl-pyrimidine-4,6-diyl)bis(1-methylhydrazone) (1) is reported. Ligand 1 was designed as a ditopic pyrimidine-hydrazone molecular strand with hydroxymethyl groups attached to the terminal pyridine rings. Coordination of 1 with Cu(ClO(4))(2) x 6 H(2)O or Cu(SO(3)CF(3))(2) x 4 H(2)O in a 1:2 molar ratio resulted in the dinuclear Cu(II) complexes [Cu(2)1(CH(3)CN)(4)](ClO(4))(4) x CH(3)CN (4) and [Cu(2)1(SO(3)CF(3))(2)(CH(3)CN)(2)](SO(3)CF(3))(2) x CH(3)CN (5). X-ray crystallography and (1)H NMR NOESY experiments showed that 1 adopted a horseshoe shape with both pyrimidine-hydrazone (pym-hyz) bonds in a transoid conformation, while 4 and 5 were linear in shape, with both pym-hyz bonds in a cisoid conformation. Coordination of 1 with Cu(ClO(4))(2) x 6 H(2)O or Cu(SO(3)CF(3))(2) x 4 H(2)O in a 1:1 molar ratio resulted in three different bent complexes, [Cu(1H)(ClO(4))(2)](ClO(4)) (6), [Cu(1H)(CH(3)CN)](ClO(4))(3) x 0.5 H(2)O (7), and [Cu1(SO(3)CF(3))](2)(SO(3)CF(3))(2) x CH(3)CN (8), where the pym-hyz bond of the occupied coordination site adopted a cisoid conformation, while the pym-hyz bond of the unoccupied site retained a transoid conformation. Both 6 and 7 showed protonation of the pyridine nitrogen donor in the empty coordination site; complex 8, however, was not protonated. A variety of Cu(II) coordination geometries were seen in structures 4 to 8, including distorted octahedral, trigonal bipyramidal, and square pyramidal geometries. Coordination of the hydroxymethyl arm in the mononuclear Cu(II) complexes 6, 7, and 8 appeared to inhibit the formation of a [2 x 2] grid by blocking further access to the Cu(II) coordination sphere. In addition, the terminal hydroxymethyl groups contributed to the supramolecular structures of the complexes through coordination to the Cu(II) ions and hydrogen bonding.
- Published
- 2010
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40. Treatment of hypervolemic or euvolemic hyponatremia associated with heart failure, cirrhosis, or the syndrome of inappropriate antidiuretic hormone with tolvaptan: a clinical review.
- Author
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Nemerovski C and Hutchinson DJ
- Subjects
- Benzazepines adverse effects, Benzazepines pharmacokinetics, Blood Volume, Dose-Response Relationship, Drug, Drug Interactions, Heart Failure mortality, Humans, Inappropriate ADH Syndrome mortality, Liver Cirrhosis mortality, Randomized Controlled Trials as Topic, Sodium blood, Tolvaptan, Antidiuretic Hormone Receptor Antagonists, Benzazepines therapeutic use, Heart Failure complications, Hyponatremia drug therapy, Hyponatremia etiology, Inappropriate ADH Syndrome complications, Liver Cirrhosis complications
- Abstract
Background: Tolvaptan is an oral nonpeptide selective vasopressin V(2)-receptor antagonist indicated for the treatment of clinically relevant hypervolemic or euvolemic hyponatremia associated with heart failure, cirrhosis, or syndrome of inappropriate antidiuretic hormone., Objective: The objective of this article was to review the pharmacology, efficacy, and tolerability of tolvaptan in the treatment of hypervolemic or euvolemic hyponatremia, heart failure, and autosomal dominant polycystic kidney disease (ADPKD)., Methods: Articles were identified using MEDLINE (1966-February 28, 2010) and EMBASE (1947-February 28, 2010). Abstracts and proceedings from the annual meetings (2007-2009) of the American Heart Association, the European Society of Cardiology, and the American Society of Nephrology were searched to identify additional relevant publications. Searches were conducted using the terms tolvaptan, vasopressin antagonist, heart failure, polycystic kidney disease, hyponatremia, drug interaction, pharmacokinetics, and pharmacology. The reference lists of the identified publications were reviewed for additional references. All clinical trials that assessed the use of tolvaptan in the management of hypervolemic/euvolemic hyponatremia or heart failure in humans were included, regardless of study design., Results: A total of 9 trials were identified. For the treatment of hyponatremia, tolvaptan was associated with significantly increased serum sodium concentrations compared with placebo on treatment days 4 (3.62 [2.68] vs 0.25 [2.08] mmol/L, respectively; P < 0.001) and 30 (6.22 [4.10] vs 1.66 [3.59] mmol/L; P < 0.001). In the clinical trials in patients with heart failure, tolvaptan at doses of 30, 60, and 90 mg/d was associated with mean weight changes of -1.80, -2.10, and -2.05 kg, respectively, versus -0.60 kg with placebo (P = 0.002, P = 0.002, and P = 0.009). Trials of tolvaptan in humans with ADPKD are ongoing. Overall, mortality rates were not significantly altered with tolvaptan compared with placebo (25.9% vs 26.3%). The most commonly reported adverse events associated with tolvaptan in clinical trials were dry mouth (4.2%-23.0%), thirst (7.7%-40.3%), and polyuria (0.6%-31.7%), all consistent with the mechanism of action of the drug., Conclusion: Based on findings from clinical trials to date, tolvaptan is effective for the correction of hyponatremia but has not been associated with significant improvements in mortality in patients with heart failure compared with placebo, and its utility in the treatment of ADPKD in humans remains to be determined.
- Published
- 2010
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41. 2-Methyl-4,6-bis-(1-methyl-hydrazino)pyrimidine.
- Author
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Hutchinson DJ, Hanton LR, and Moratti SC
- Abstract
In the title compound, C(7)H(14)N(6), the amine groups of the two methyl-hydrazino substituents are orientated in the opposite direction to the methyl substituent at the 2-position of the pyrimidine ring. The mol-ecule is almost planar with only the two amine N atoms lying substanti-ally out of the mean plane of the pyrimidine ring [by 0.1430 (2) and 0.3092 (2) Å]. The H atoms on these amine groups point inwards towards the aromatic ring, such that the lone pair of electrons points outwards from the mol-ecule. Each mol-ecule is linked to two others through N-H⋯N hydrogen bonds between the two amino groups, forming a one-dimensional chain in the [010] direction. Offset face-to-face π-π stacking inter-actions between the pyrimidine rings organize these chains into a two-dimensional array [centroid-centroid distance = 3.789 (2) Å].
- Published
- 2009
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42. Stability of extemporaneously prepared moxifloxacin oral suspensions.
- Author
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Hutchinson DJ, Johnson CE, and Klein KC
- Subjects
- Administration, Oral, Chemistry, Pharmaceutical, Chromatography, High Pressure Liquid, Drug Compounding, Drug Stability, Drug Storage, Fluoroquinolones chemistry, Moxifloxacin, Pharmaceutical Vehicles, Suspensions, Tablets, Anti-Infective Agents chemistry, Aza Compounds chemistry, Quinolines chemistry
- Abstract
Purpose: The stability of extemporaneously prepared moxifloxacin oral suspensions was studied., Methods: An oral suspension of moxifloxacin 20 mg/mL was prepared by thoroughly grinding three 400-mg tablets of moxifloxacin in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of each formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and were stored at room temperature (23-25 degrees C). A 1-mL sample was withdrawn from each of the six bottles with a micropipette immediately after preparation and at 7, 14, 28, 60, and 90 days. After further dilution to an expected concentration of 8 microg/ mL with sample diluent, the samples were assayed in duplicate by stability-indicating high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration., Results: At least 99% of the initial moxifloxacin remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth in any sample., Conclusion: Extemporaneously compounded suspensions of moxifloxacin 20 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 2-oz amber plastic bottles at room temperature.
- Published
- 2009
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43. Human papillomavirus disease and vaccines.
- Author
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Hutchinson DJ and Klein KC
- Subjects
- Female, Humans, Male, Multicenter Studies as Topic, Papillomaviridae immunology, Papillomavirus Infections complications, Papillomavirus Infections epidemiology, Papillomavirus Vaccines adverse effects, Randomized Controlled Trials as Topic, United States epidemiology, Uterine Cervical Neoplasms etiology, Papillomaviridae pathogenicity, Papillomavirus Infections prevention & control, Papillomavirus Vaccines classification, Papillomavirus Vaccines immunology
- Abstract
Purpose: Human papillomavirus (HPV) disease and vaccines and several controversial issues associated with vaccine administration are reviewed., Summary: HPV infection is the most common sexually transmitted disease in the United States. It is estimated that 20 million individuals are currently infected with HPV, with 6.2 million new infections occurring each year. Although most HPV infections are benign and are often cleared without clinical sequelae, persistent infections are associated with the development of cervical cancer in women and genital warts in both women and men. The identification of the most common disease-causing HPV types has led to the development of a quadrivalent vaccine and a bivalent vaccine. The prophylactic administration of the quadrivalent vaccine has resulted in a 96% efficacy in preventing persistent infection associated with HPV types 6, 11, 16, and 18. Similar to the quadrivalent vaccine, the bivalent vaccine is highly efficacious (96%) in preventing persistent infection against vaccine-specific HPV types (HPV-16 and HPV-18) among women who were HPV seronegative at the time of vaccination. However, many controversial issues still remain regarding routine administration and widespread acceptance. These include appropriate age at time of vaccination, parental concerns, vaccination of men or women age 26 years or older, inadequate long-term efficacy and safety data, and potential for nonvaccine-related strains to emerge as prominent oncogenic serotypes., Conclusion: HPV vaccines provide a high level of protection for seronegative women against persistent infection and precancerous cervical lesions associated with vaccine-specific HPV types. However, many controversial issues still remain regarding the vaccines' routine administration and widespread acceptance.
- Published
- 2008
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44. Metabolism and selective effects of 1-beta-D-arabinofuranosylcytosine in L1210 and Host tissues in vivo.
- Author
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Chou TC, Hutchinson DJ, Schmid FA, and Philips FS
- Subjects
- Animals, Ascitic Fluid cytology, DNA, Neoplasm biosynthesis, Idoxuridine metabolism, Male, Mice, Mice, Inbred C57BL, Mice, Inbred DBA, Thymidine metabolism, Tritium, Cytarabine analogs & derivatives, Cytarabine blood, Cytarabine metabolism, Cytarabine pharmacology, Intestine, Small metabolism, Leukemia L1210 metabolism, Liver metabolism
- Abstract
The selectivity of action of 1-beta-D-arabinofuranosylcytosine (ara-C) against leukemic cells was studied in vivo. Dynamic state tissue levels of ara-C and of its mono-, di-, and triphosphate (ara-CTP) were measured in L1210 leukemic cells and in C57BL x DBA/2 F1 host tissues at different times after various doses of the agent. The levels were correlated with inhibition of thymidine incorporation into DNA and with cytocidal effects as measured by loss of isotopically prelabeled DNA. ara-CTP levels, but not those of the mono- and diphosphates of ara-C, were higher in leukemic cells and in host cell renewal systems than in other host tissues. DNA synthesis was equally inhibited by similar levels of ara-CTP in ascitic L1210 cells, in leukemic infiltrates in liver, and in small intestine. However, L1210 cells accumulated higher levels of ara-CTP for longer periods than did small intestine, and correspondingly the inhibition of DNA synthesis was greater and more prolonged in leukemic cells. ara-C caused greater losses of prelabeled DNA in ascites cells and in infiltrated liver than in host small intestine. It appears that the differential net tissue level of ara-CTP and its duration are the determinants of chemotherapeutic efficacy of ara-C against L1210 leukemia. ara-C was the predominant nucleoside present in hydrolysates of ara-CTP fractions. By contrast, 1-beta-D-arabinofuranosyluracil predominated in hydrolysates of monophosphate nucleotide fractions from ascites cells, liver, small intestine, and blood. Monophosphate nucleotide was also present in ascites fluid and plasma.
- Published
- 1975
45. Notes on continuing education.
- Author
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Hutchinson DJ
- Subjects
- American Nurses' Association, Employment, Faculty, Nursing, Humans, Teaching methods, United States, Education, Nursing, Continuing trends
- Published
- 1980
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46. Determination of copper in infant formula by graphite furnace atomic absorption spectroscopy with a L'vov platform.
- Author
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Hutchinson DJ, Disinski FJ, and Nardelli CA
- Subjects
- Humans, Indicators and Reagents, Infant, Octoxynol, Polyethylene Glycols, Spectrophotometry, Atomic, Copper analysis, Infant Food analysis
- Abstract
A rapid method for the determination of sub-part-per-million levels of copper in infant formula, which does not require decomposition of the sample matrix before analysis, has been developed. The method uses L'vov platform graphite furnace atomic absorption spectroscopy (GFAAS), a technique that greatly reduces matrix interferences limiting the applicability of normal GFAAS. The sample preparation consists of dilution of a weighed sample of infant formula to a known volume with a 0.5% solution of Triton X-100 in deionized water. The accuracy of the method, as assessed from the results of overspike recovery studies (96.5-101.3% recovery) for different matrix types and comparison to results generated with alternative methodologies, can be considered excellent. The overall precision of the method ranges from 2.5 to 4.3% RSD for different matrix types.
- Published
- 1986
47. Absorption of deoxyribonucleic acid by mouse lymphoma cells.
- Author
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SIROTNAK FM and HUTCHINSON DJ
- Subjects
- Animals, Mice, Biochemical Phenomena, DNA metabolism, Lymphoma metabolism
- Published
- 1959
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48. Metabolism of resistant mutants of Streptococcus faecalis. III. The action of 6-mercaptopurine.
- Author
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BALIS ME, HYLIN V, COULTAS MK, and HUTCHINSON DJ
- Subjects
- Humans, Enterococcus faecalis drug effects, Mercaptopurine pharmacology
- Published
- 1958
49. Editorial: Certification: a new impetus to continuing education.
- Author
-
Hutchinson DJ
- Subjects
- Certification, Education, Nursing, Continuing, United States
- Published
- 1973
50. Development of resistance to 4-amino-N10-methyl pteroylglutamic acid (Amethopterin) by Streptococcus faecalis.
- Author
-
BURCHENAL JH, WARING GB, and HUTCHINSON DJ
- Subjects
- Amino Acids, Biochemical Phenomena, Enterococcus faecalis, Folic Acid, Folic Acid Antagonists pharmacology, Methotrexate, Streptococcus
- Published
- 1951
- Full Text
- View/download PDF
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